Topic 1: Norms and Meaning of Test Scores {by 9/8}

Based on the text readings and lecture recording due this week consider the following two discussion points: (1) In your own words, provide a general description of the difference between criterion/domain-referenced instruments and norm-referenced instruments.  Why is it important to understand this difference?  (2) What are your thoughts on your understanding of the normal distribution?  In other words, does it generally make sense (explain) or is it still a little confusing (that’s okay – explain)?

 

Your original post should be posted by 9/8.  Post your two replies no later than 9/10.  *Please remember to click the “reply” button when posting a reply.  This makes it easier for the reader to follow the blog postings.

75 Comments (+add yours?)

  1. Tiana Faulkner
    Sep 02, 2022 @ 20:32:47

    For criterion/domain-referenced instruments your responses or grades are not being compared to other people’s responses or grades. There are no comparisons being made, rather “levels of mastery” or passing and failing a test with cut off scores. While norm-referenced instruments are used to compare a person’s results to other people’s results. These being the people that were used to make the instrument.
    These two instruments are used in different situations, it is about knowing what type of test you are administering, when it should be used, and how they should be interpreted. You would not use the norm-referenced instruments on regular academic tests that are based on how well you answered the questions individually that add up to a pass or fail grade, that would not make sense; rather you would use them in instances such as percentiles for your weight and height at the doctor’s office those being based on how others (those who were used to create the test) measured on the same scale.
    My understanding of the normal distribution is pretty surface level, it has to do with the normal curve, or the “bell curve”. Like stated earlier, it is used to understand the things measured using the norm-distribution instruments, such as percentiles for weight and height at the doctor’s office. It has to do with the standard deviations, percentiles, T-scores, standard scores, means, modes and attempting to creating that normal curve most people like to see. I am not sure it is about being confused about the information and more about just not really knowing if I know or understand enough of the information.

    Reply

    • Becca Boucher
      Sep 05, 2022 @ 13:07:39

      Hi Tiana! I really like how you tied the use of a normal distribution back into the norm-referenced instruments. I feel like it’s really obvious, but that kind of went over my head. I never put two and two together to fully understand that a normal curve would show the data collected from a norm-referenced instrument. Your point really tied together two parts of this chapter for me, so thank you!

      Reply

    • Jack Halliday
      Sep 10, 2022 @ 08:26:10

      Hi Tiana, I also never out two and two together with norm-referenced instruments relating to a normal distribution. To be honest, I feel a bit silly for not doing so but it does make logical sense. For some of the concepts I also feel like I understand it, I just don’t know if I understand it well enough. Especially when it comes to the T and Z scores, but I’m sure all we need is a refresher on the concepts and then we’ll be right back to it.

      Reply

  2. Alyson Langhorst
    Sep 03, 2022 @ 19:47:29

    Criterion referenced instruments take an individual’s score and compare it to a set of criteria. These types of instruments look for level of ability/understanding rather than an average. An example of this would be a driving test. Your score (your ability to drive) is compared to what the state has deemed to be a passing score (the basic knowledge and mastery of skills that are needed in order to drive safely). Driving test proctors aren’t comparing your score to the average person’s score. Instead, they are comparing your ability to drive and understanding of the rules/laws of the road to the already predetermined minimum score and seeing if you are able to pass it. In the example of a driving test, If you get let’s say a 95% (maybe you messed up on parallel parking once) and the passing score was a 90%, then you would pass because the state has set the passing score to mean that you need to know/be able to demonstrate at least 90% of the rules.
    Norm referenced instruments take an individual’s score and compare it to the average score for that instrument. The average score is determined by having a large sample of participants (a norming group) take the instrument and then running those scores to get the mean score. This way, when you take one of these instruments, they can take your score and compare it to a large sample to see where your score fits in compared to everyone else. An example of this would be the IQ test. An individual’s score is compared to a norm.
    The difference between norm referenced and criterion referenced instruments is how the information is used. Tests that are norm referenced, like the IQ test, look to see how an individual is doing compared to others. Simply put, they don’t have a set score that an individual needs to meet in order to pass. Criterion referenced instruments, however, are comparing an individual’s score to a set standard and seeing if the individual does or does not meet the requirements to pass. It’s important to understand the difference between norm referenced and criterion referenced because you can’t interpret the scores in the same way. A score of 80 on the IQ test does not mean the same thing as getting an 80 on a licensing exam- both scores have different values since they are measuring two different things. Scores on a criterion referenced test are looking to see how many you got right/wrong whereas scores on a norm referenced test are looking at what percentile you scored in.
    I think I understand what normal distribution is. Simply put, the average (most) scores are in the middle of the curve which creates a peak that gradually declines in both directions. This would be interpreted as a majority of people tend to score in the middle of the curve and then less and less people tend to score farther away from the peak. 1 SD (standard deviation) would have the largest cluster of scores, 2 SD’s away would have fewer clusters of scores (compared to 1 SD away), and 3 SD’s would have even fewer (compared to 2 SD’s away). I am a bit confused about skewed distributions though. Specifically, why are positively skewed distributions interpreted as having lower scores and vice versa for negatively skewed distributions? I tried following the example on the next page but I’m still confused.

    Reply

    • Emily Forde
      Sep 08, 2022 @ 10:27:08

      Hi Alyson!

      I really like the example you gave about getting your driver’s license, I think that is a great way to understand criterion-referenced instruments. I think for this area it is best to have a criterion-referenced test because it ensures that the people that will be driving must have a certain level of understanding and mastery, which is important for the safety of themselves and others. When safety or well-being are involved do you feel like a criterion-referenced test may be the most effective?

      Reply

    • Wendy Fernandes
      Sep 09, 2022 @ 21:54:44

      Hi Alyson!

      I found your driving test example interesting because I did not do well on the parallel parking part of my test (the rest was fine), but if it was a norm referenced test then I may not have passed depending on how much weighting that section was given and how others did. I find parallel parking to be something that people are either great or terrible at, so it is a good thing for me that it was a criterion referenced instrument! I agree with both you and Emily that this sort of subject really should be criterion based while for psychological assessments a percentile ranking is more useful in determining deviation from the norm.

      Reply

  3. Becca Boucher
    Sep 05, 2022 @ 13:01:35

    Norm-referenced instruments compare the score of the individual taking the instrument to the scores of other individuals who have taken the same instrument. For example, when children are weighed at the doctor’s their weight is compared with the weight of other children their age to determine if their current weight is healthy or not.
    However, with criterion- referenced instruments, the score of the individual is compared to a pre-established standard. An example of a criterion-referenced instrument is a test you would take in school. How well you do on an exam is not determined by comparing your score to the scores of your peers taking the same test, but instead by a set standard. This standard determines what you need to know in order to do well on the exam and what counts as having mastered the material as well. This is known as the mastery cut-off.
    It is important to understand this difference because when you get a score on a test, the score doesn’t mean anything until it is put into context. However, that context differs from norm-referenced instruments to criterion-referenced instruments. So, if you are incorrectly referencing your score, you will have the incorrect context and therefore the meaning behind your score could differ greatly from what it is supposed to be.
    Normal Distributions make sense to me. The mean, median, mode, and standard deviations of a normal distribution are generally easy numbers to remember and work with. Getting back into using a normal distribution, z-scores, and T scores again, I will definitely need a bit of a refresher in seeing how they really work in a problem. However, once I see a problem again and work with it, the normal distributions and all the math will come back quickly.

    Reply

    • Tiana Faulkner
      Sep 05, 2022 @ 21:18:06

      Hi Becca! I definitely agree with you last point, trying to get back into using all of these different numbers is going to need some getting used to. Math has never really been my strong suit I was slow to pick things up with stats as well but once I get back into using these numbers again and seeing them in actual examples I feel like I will be used to seeing them again.

      Reply

    • Abby Sproles
      Sep 07, 2022 @ 22:02:40

      Hi Becca, I totally agree with your explanation of the difference between norm-referenced and domain instruments. Your description of how domain instruments may have a ‘mastery cut-off’ made me think about how arbitrary some of these demarcations may be. What amount of knowledge constitutes as ‘mastery’? Are there truly objective methods of identify this cut off point?

      Reply

    • Jack Halliday
      Sep 10, 2022 @ 08:10:30

      Hi Becca, it seems like you have a good grasp on the concepts. In your post you really highlighted the importance of context, and I think that it’s very important to keep in mind when scoring and analyzing the scores. I agree with what you said at the end, especially with the Z and T scores, it has been many moons since I last used them, and a refresher will be helpful. Especially, like you said, how they’re used in problems. But, also like you said, I’m sure once we start using them again it’ll all come back to us.

      Reply

  4. Jack Halliday
    Sep 05, 2022 @ 13:06:42

    The main difference between domain-referenced instruments and criterion-referenced instruments has to do with the scoring of the respective instruments. With norm-referenced instruments the users score is compared to the scores of other people who have taken that same instrument. The norm (the group of scores used to compare an individuals’ score to) can vary greatly in size; for example, it can be as large as the 2,000 other adults who have taken a personality inventory, or it can be a smaller scale such as a teacher scaling a test grade, in which case your scores are being compared to only your fellow classmates. In criterion-referenced instruments an individual’s score is being compared to a pre-established standard. When utilizing these tests, it is important that the person interpreting the scores understands the domain that was being measured. These types of instruments can also have a mastery component. This is essentially a super passing grade, if you meet the established score for mastery than you get the special prize. There are difficulties involved when developing adequate criterion-references instruments. The first one being that since these tests are designed to measure an individual’s knowledge level/performance in a particular domain, it must accurately measure said domain. It can also be tricky to establish what exactly is the mastery level cut-off, and how strictly that should be enforced. The difference between these two types of instruments is very important when it comes to interpreting the results. Interpreting criterion-referenced results is straightforward, they either made it or they didn’t. For norm-references results statistics are often used to aid with the interpretation.

    Normal distributions are honestly straight-forward for me. This is the third time in my academic career that I have been exposed to them, so any points of confusion have been cleared up by now. The measures of central tendency all being the same and the empirical rule make working with normal distributions clear. It’s been a while since I’ve calculated Z and T Scores so it might take a few tries to get back into the swing of things for that. This whole stanine thing is new, and it’s not exactly crystal clear but once we start working with them, I’m sure my confusion will clear up.

    Reply

    • Alyson Langhorst
      Sep 06, 2022 @ 19:51:57

      Hi Jack!

      You gave great examples of different types of norming groups. I really liked that you mentioned how the sizes and populations of these groups can vary greatly. Both of these factors are important for determining the validity of said test. You also bring up a valid point that criterion-referenced tests are a bit more challenging in the scoring, specifically when level of mastery is being established. With certain fields, there could be discourse and controversy about what should be a passing score and what should be considered mastery. I also never heard of stanine before but I agree that it’ll probably just take a bit of work/practice to understand it.

      Reply

    • Esther Konadu
      Sep 07, 2022 @ 19:17:08

      Hi Jack,

      While this is also my third time being exposed to this, I feel like this is helpful to refresh my memory and get prepared to look at statistics. The stanines are certainly a new topic for me as well. Reading it in the textbook left me with more questions than answers. I can only hope that I grasp it after hearing it a few more times!

      Reply

  5. Abby Sproles
    Sep 05, 2022 @ 13:12:18

    Domain-referenced instruments are used when comparing an individual’s score to a standard or set of criterion. For example, many of the tests in our program will be domain-referenced since we will be evaluated on if we have acquired the knowledge taught in a specific course. On the other hand, norm-referenced instruments are used when comparing an individual’s scores to the group of individuals who previously were administered the same instrument, such as the GRE. My scores on the exam are given in a percentile rank of how they compared to other test takers’. It is important to understand the difference between the two when interpreting and sharing results with the client to ensure they understand their results and how they compare to others. The score of an instrument may be inaccurately interpreted and therefore could lead to harm to the client such as unnecessary or inappropriate interventions.
    The normal distribution makes sense. The normal distribution illustrates the mean in the center of a bell curve, with the majority of scores in the center, and less on both sides of the mean. I think that the normal curve is a helpful visual tool to see how much (in standard deviations) a particular score varies from the mean, and what percentage of people may also have a similar score. What is a little confusing is how to interpret results that are not on a normal distribution such as bimodal or skewed. Would we interpret scores as the distance in standard deviations from the mean similarly to a normal distribution?

    Reply

    • Tiana Faulkner
      Sep 05, 2022 @ 21:23:52

      Hi Abby! I liked how you tied the different instruments back to the tests we will be using in regard to counseling. I had just tied them back to general examples related to school. I definitely agree with you when you stated that it can cause serious harm if the results are not interpreted correctly. In my head I was thinking more general as in you could just be wrong about how you look at a students test scores in school or where they fall on the growth chart at the doctors office. Also, I definitely have a hard time with some of the statistical numbers we will be covering. Reading things within a normal distribution does not seem to difficult, it is when the numbers start to get a bit wacky that I begin to lose my understanding. So that is definitely a great question.

      Reply

    • Lucy Rising
      Sep 08, 2022 @ 13:16:47

      Hey Abby, I like how in your post you effectively explained the differences between the two reference instruments, provided good examples of each, and then took it the extra step further and applied them to how we will be using them in this program/in our future careers. You also stressed the importance of both reading the instruments correctly for our clients and interpreting/explaining them in an understandable and comprehensive manner to them, which are things we ought to keep in the back of our minds while learning in this course.

      Reply

  6. Lucy Rising
    Sep 06, 2022 @ 11:22:25

    The way I understand it, the main difference between norm-referenced and criterion-referenced instruments is in how an individual’s score on an assessment is measured. In norm-referenced instruments, an individual score is measured in reference to other scores on the same assessment. Meaning that how one performs is directly affected by how others perform on the same assessment. For criterion-referenced instruments, one’s score is measured and evaluated in reference to some preexisting standard or means of measurement. The difference here is a matter of “I got a 90% on this exam because I performed better than 90% of the others who took this exam” versus “I got a 90% on this exam because I answered 90% of the questions of the exam correctly.” While in both of these cases the individual scored a 90% on the exam, how they received that score differed, and as a result the score of 90% means two different things in each case.
    I understand the concepts of distribution and normal distribution fairly well. I know I am just going to have to brush up on how to do the actual “math” of it all. Ideologically they make sense, but applying these concepts to actual measurements and analyzing them will be new territory for me.

    Reply

    • Alyson Langhorst
      Sep 06, 2022 @ 20:10:34

      Hi Lucy!

      I really liked the 90% example you gave! I think it illustrates the main point that these tests, while both are important, have different applications and interpretations. To add onto that point, the outcomes of both tests are widely different. As you said, getting a 90% on a test because you answered 90% of the questions correctly will allow you to move onto the next section or the next grade. Subsequently, if you get a 50% on a test because you only got 50% correct, then it means that you might not be able to move on. Whereas, norm-referenced testing is more to look at your place in relation to others in a given area. For example, if a person does score 3 SDs away from the mean in, then the outcome might be that the person is able to access more resources/support to help them in that given area.
      I also struggle with the math of it and the actual application of it. For me, it’s been a minute since I’ve taken psych stats and psychometrics. I’m hoping it’s like riding a bike, just needing to brush up on the skills of actually doing it.

      Reply

    • Whitney Andrew
      Sep 06, 2022 @ 22:15:22

      Hi Lucy!

      It was such a smart idea to compare the different instruments in terms of exams since we are all super familiar with scores like that! The example even helped solidify the difference better for myself even though I am familiar with these terms already!
      I definitely feel like I’m in the same boat as you on needing to brush up with actual math because its been way too long since I’ve put these stats into action. You will do absolutely fine though so try not to stress!

      Reply

    • Becca Boucher
      Sep 08, 2022 @ 15:18:54

      Hi Lucy! I really like how you broke it down into the “I got a 90% because I scored better than 90% of people” vs. ” I got a 90% because I got 90% of the questions correct”. That was such a great way to break it down! I found it difficult to put into words how a criterion-referenced instrument score worked, and your comparison example was really effective and helpful!

      Reply

  7. Stephanie Lugo
    Sep 06, 2022 @ 12:26:31

    Norm-referenced instruments are used most often to compare an individual’s score with other individuals’ scores or grades when they have taken the same instrument. On the other hand criterion/domain-referenced instruments are used when an individual’s response or grades are not compared with other individuals’ responses. Whether individuals’ responses are or are not compared is the biggest difference between criterion/domain-referenced instruments and norm-referenced instruments.

    Norm-referenced instruments and Criterion/domain referenced instruments are used in many different situations. Once you determine the specific test that you want to administer then you can better determine what type of referenced instrument you should use to interpret and grade the test. Norm-referenced instruments are not commonly used in academic settings as most academic tests are graded and interpreted based on the individual’s single responses; responses from other individuals are not commonly taken into consideration during the grading process. With Criterion/domain referenced instruments each person’s individual response is graded individually and not compared to others.

    Norm-referenced instruments are most commonly used to measure certain comparable scores. One common example of this is an IQ score. When an individual has an IQ score that singular score is compared to the normal score rate range and you are then placed in certain categories. People with high IQ ranges are compared, people with average IQ ranges are compared, and people with lower IQ ranges are compared. Yet in this situation, all individuals’ scores are compared to one another and not individually scored.

    It’s important to understand the difference between Norm-referenced instruments and Criterion/domain-referenced instruments because not all tests can be compared and not all test scores mean the same. If you use the wrong type of instruments when scoring an open question exam then you will have a fault in your grading system. Comparing individual answers to open questions will not be possible because each person’s answers will be different. This is why it’s important to take time to figure out what type of referenced instruments are supposed to be used when interpreting individual scores or answers.

    I do feel that I understand the basics of what a normal distribution is. The mean, median, mode, range, and standard deviations are relatively easy to understand and comprehend especially when you have a clear set of data. In my undergraduate, I took a class all about Statistics in Social Sciences, and the majority of this class centered around the normal distribution and the above factors. One thing I will need a refresher on is the difference between z-scores and t-scores. I briefly remember the difference between these two types of scores, but I believe once I better see how they are used I will quickly remember what I have previously learned.

    Reply

    • Whitney Andrew
      Sep 06, 2022 @ 22:26:54

      Hi Stephanie

      I found it super helpful that you broke up the discussion of norm-referenced vs. criterion referenced into individual definitions and then compared the two. This is perfect practice for abnormal the way Professor Doerfler talks about his exam set up!

      I know it will help to talk about it more in class, but it seems as though the biggest difference to take away from z-scores and t-scores is that a t-score is a modified z-score that is a whole number so it is easier to work with. The process to obtain a t-score is manipulating the z-score so that there are no decimals or negatives to create a more ‘norm’ version of a z-score. That is not to say that t-scores can be used for every assessment as some testing cannot be analyzed if the population is not normalized.

      Reply

    • Magdalen Paul
      Sep 08, 2022 @ 23:38:52

      Hi Stephanie! I like how simply and concisely you explained the criterion-referenced instruments in that each person is graded individually and not compared to others. This definitely resonates with the many grades we have all received during our years of schooling, receiving the letter or number grade on an exam and identifying exactly how that grade came to be based on # correct for you as an individual. If the teacher had said that a passing grade was 70 and you individually received an 80, you would have been evaluated based on whether you met/surpassed the set domain. Meanwhile, if after grading us individually, the teacher then wanted to understand how well you did comparatively to the class, this information would involve a norm-referenced instrument (perhaps just for the teacher’s insight on your standing relative to others). It is interesting how two instrument types lead to such different conclusions with unique implications.

      Reply

  8. Megan VanDyke
    Sep 06, 2022 @ 14:33:06

    Criterion/domain-referenced instruments and norm-referenced instruments are different based on what the individual/participant’s score is being compared to. Criterion-referenced instruments take an individual’s score and compare it to a pre-designated standard that serves as the “cut-off” for whether the induvial passes or fails. For example, as mentioned in our first class, graduate students in the clinical counseling program must have a minimum of a B- to pass a course. An overall score of 78 means that the subject is not yet mastered, whereas an 82 is barely sufficient for moving on. On the other hand, norm-referenced instruments take an individual’s score and compare it to other individuals’ scores. However, the other individuals’ scores must be from the same instrument. For example, a doctor would not want to compare a 12-year-old female’s BMI to that of a 40-year-old male. They would compare the patient to other 12-year-old females to gain more accurate information. Based on the given examples, it is important to discern which instrument should be used to provide accurate results that can be easily interpreted in each context.
    I have a good understanding of interpreting normal distributions and where scores might fall within them. However, I need more help with Z-scores, T-scores, and stanines. I did not get much time to learn these concepts in undergrad as I was taking statistics when classes abruptly went remote. I am also going to need help with calculating scores and how to create a normal and skewed distribution.

    Reply

    • rena yaghmour
      Sep 07, 2022 @ 22:29:40

      Hi Megan,
      I really like the examples you gave, they really portray the difference between the two instruments nicely and help give a better understanding. I especially liked the BMI example you gave. It was easy to visualize and helped me see that when comparing two individuals it has to be compared fairly and not just random comparisons between two people.

      Reply

    • Ariannah Zagabe
      Sep 10, 2022 @ 10:57:03

      Hello Megan,
      I liked how you used our grad program as an example about criterion-referenced instruments. It’s a perfect example of how those kind of scores are compared to a set standard.
      I’m also in the same boat as you in needing more help with understanding Z-scores and T-scores (I took my undergrad statistics class remotely as well which I feel made it harder to understand the concepts).

      Reply

  9. Whitney Andrew
    Sep 06, 2022 @ 22:10:16

    The difference that sets apart criterion / domain-reference instruments from norm-referenced differences is what the individual score is compared to. In criterion-reference instrument, the comparison of an individual’s score is to an established standard, whereas in norm-reference instrument the individual score is compared to other individuals within that same scoring. It is important to know this difference to better interpret scoring. It is best to use norm-reference for comparison to the norm of other individuals in the specific group, while criterion-reference is better for basic skill interpretation.

    The normal distribution, as I understand it, is the ideal data distribution. The norm is centered right in the middle, having the majority of cases in the middle to represent the norm, leaving the outliers in the curve to be outside of the norm. In my experience, it becomes more difficult to work with distributions other than the normal curve as the majority of data is skewed away from the norm. To me, it makes sense as the norm is ‘normal’ and therefore centered and neat. It visually represents the ideal case and those within the 68% are in the ideal majority for the norm.

    Reply

    • Lucy Rising
      Sep 08, 2022 @ 13:10:05

      Hey Whitney, I liked how you offered examples on when it is best to use the different referenced instruments. It definitely helps us to better conceptualize not just how we ought to use these tests but how they measure what they are aiming to measure when given examples of /when/ we /should/ use them as opposed to just what they compose of. (I hope my slashes conveyed italics well enough lol)

      Reply

    • Magdalen Paul
      Sep 08, 2022 @ 23:46:35

      Hi Whitney! I like how you explained your understanding and liking of the normal distribution. I totally agree that, because it is symmetrical and therefore visually appealing, it is easier to understand and work with. A normal curve is easier to conceptualize and it would be wonderful if every distribution could be that way! I definitely look forward to learning more about other distribution forms so that, hopefully, they can someday feel just as simple to navigate. It is interesting also how non-normal distributions seem harder to understand/work with, yet may lead to the most interesting or unexpected findings.

      Reply

    • Ashley Millett
      Sep 09, 2022 @ 18:03:13

      Hi Whitney,

      I agree with you on how important it is to know the difference between the two. Once we know the difference between the two, we are able to interpret the scores in the best way possible. I like how you put it when it is the best time to use both norm-referenced and criterion reference instruments. With knowing when to use either or, we would then know how to interpret the scores and what we are looking for.

      Reply

  10. Chandal Powell
    Sep 06, 2022 @ 23:51:17

    The main difference between criterion referenced instruments and norm referenced instruments is criterion makes a comparison of one’s test scores to a pre specified standard or criteria and norm makes a comparison to other individuals who have already taken the same test. Criterion-referenced instruments evaluate an individual’s performance based on a pre-existing set of standards or criteria. In other words, it is used to figure out whether an individual has achieved the results expected based on the established standards. Once achieved this would mean that the individual is displaying mastery of the content presented or the specific skill being evaluated. Criterion–referenced instruments can be used to decide how well a student understands the material presented in a class. For example, mid-term exams are used to figure out if students have a good understanding of the material presented. This is shown by whether the student passes or fails the exam. Norm-referenced instruments evaluate individuals’ performances by making a comparison to ‘the norm.’ The norm being a similar group of individuals who were used in making the instrument. For example, an individual’s SAT scores are compared to a normative sample to decide if the individual is a high or low achiever.
    It is important to understand the difference between criterion and norm referenced instruments because when you receive a test score, it needs to be evaluated in context. So, understanding the meaning behind a score based on the instrument used can determine the proper interventions used to provide effective care to a client for example.
    I think I understand the basics of normal distribution. With numbers (data) understanding the mean, median, mode and standard deviation should be relatively easy. However, statistics was a class I took some time ago so I will need a refresher on understanding t and z scores, standard deviation, and skewed distribution.

    Reply

  11. Gitte
    Sep 07, 2022 @ 08:26:48

    1. Norm-referenced instruments are individual’s outcomes or scores that are compared to each other using the same instrument or test. Norm-referenced instruments, for example, can be standardized tests that compare individuals’ scores to one another, such as percentiles. This is different than criterion-referenced instruments, this focuses on an individual’s outcome and compares it with the standard level. These are mastery-level tests, when taking a driver’s test, you need to pass with a specific score to get your driver’s license. Knowing the difference between norm-referenced and criterion-referenced tests is important so you can choose the best instrument for the situation. Additionally, these instruments have different scoring, and is important to know what your score means so you can provide meaning with the score. Otherwise, the score is just a number.
    2. I believe I have a good understanding of the normal distribution, as I remember learning this in undergrad. Reading this chapter was a good refresher as it has been a few years since I took statistics and psychometrics. The normal distribution is what you want your data to look like, having the norm in the middle (mean, median, and mode) and the rest of the cases on the other sides of the norm. Every time I think of the normal distribution, I picture the normal curve as it is easier to understand with a visual. However, the chapter reviewed percentiles which still are a bit confusing to me and I think having another review with T and Z scores would also be helpful.

    Reply

    • rena yaghmour
      Sep 07, 2022 @ 22:09:38

      Hi Gitte,
      I also used to the example of getting your license! I think it made it easier for me to understand the difference more because when I think about it, the criterion/domain referenced instrument sounds like there is more pressure to perform a certain way where as the other one it’s not as much. Plus, a drivers test is so nerve wracking let alone having to perform perfectly.

      Reply

    • Melissa Elder
      Sep 09, 2022 @ 12:06:31

      Gitte,
      I really enjoyed your example of the driver’s test, I think it is so helpful to connect these instruments back to something we are familiar with to really get a good understanding of it. I agree that another review of T and Z scores would be helpful, however, I believe they both work closely with the raw scores but there is a difference between the two, I get them confused though.

      Reply

  12. Esther Konadu
    Sep 07, 2022 @ 13:16:14

    Criterion-referenced instruments focus on comparing someone’s score to the standard score, while norm-referenced instruments compare or contrast someone’s scores to others’ scores. Understanding this difference not only makes it easier to identify the two, but it becomes easier to apply them. Criterion-referenced instruments are like the lessons on Duolingo. You must answer questions, and your knowledge determines if you mastered the section or not. Norm-referenced instruments are like going over an exam in class; you compare your score with others to see where you might have gone wrong.

    From what I remember (and from reading), the normal distribution makes sense to me: there are places where a score/value could fall, and these can be between one to three standard deviations away from the mean. The distance away from the mean can be positive or negative. When there are more values within one standard deviation from the mean, the distribution is more normal (in terms of shape). When the values are more skewed, the curve reflects that and leans a certain way.

    Reply

    • mikayladebois
      Sep 07, 2022 @ 15:07:40

      Hi Esther, I love the Duolingo reference! I also liked your visual of a score being a distance away from the mean, I haven’t heard that before but it makes sense to me. That is similar to something like a graph where you can have positive or negative numbers, depending on which way they go away from the origin.

      Reply

    • Grace Ling
      Sep 07, 2022 @ 23:00:50

      Hey Ester! I also enjoyed your example of Duolingo as a criterion-referenced instrument. In learning a language, it is all about mastery and there is no point in competing with others, though on Duolingo they do show you other people’s scores as a means of creating a sense of competition of mastery over a language.

      Reply

      • Esther Konadu
        Sep 08, 2022 @ 14:10:53

        Right, I forgot about the scoreboard! Well, I guess if you pretend it is not there then maybe my example still works. Thank you for pointing it out!

        Reply

  13. mikayladebois
    Sep 07, 2022 @ 15:03:44

    In my mind, I see criterion or domain-referenced instruments as the competency tests administered in schools. The score of the individual is compared to a predetermined number that comes from an impersonal or authoritative figure. Norm-referenced instruments are more like a track meet or sports competitions. One’s performance is only seen in the light of the people around them. The person who wins gold at the Olympics does not have to swim the fastest 50 meters ever, they just have to swim faster than the people in the pool at that time. This is an important distinction because a criterion-referenced instrument is most likely a consistent measure, normed instruments have the potential to be different every time. Unless the predetermined number is 95, someone who scores a 90 on their spelling test will pass that test. A thrower might have an off day and throw 5 meters under their personal record but still, win their meet.
    My thoughts on general distribution are still pretty basic. I can make sense of the bell curve and the corresponding percentages of 68, 95, and 99.7, but how one arrives at the standard deviation, z score, T score, and why, is still confusing to me (so essentially the math portion of everything). I felt that the book went through some of the concepts a bit fast, so hopefully having the information expressed verbally in class will help me connect some of these dots.

    Reply

    • Esther Konadu
      Sep 07, 2022 @ 19:09:23

      Hi Mikayla! I love the example of the Olympic race for norm-referenced instruments. The best part is that I can visualize exactly what you mean by it. I am certainly a bit more excited to start learning more about these concepts now that I understand them!

      Reply

    • Taylor Poland
      Sep 09, 2022 @ 09:41:50

      Hi Mikayla! I think that your connection between norm-referenced instruments and the Olympics was very helpful. The concept of norm-referenced instruments seems pretty straightforward, but I really liked the way you defined it (“one’s performance is only seen in the light of the people around them”). I can apply this idea to throwing at competitions which will help me remember and reinforce this concept. I also agree that the book went over z scores and t scores rather quickly, but I think class lecture and discussion will refresh our memories from stats with Professor Zhang/ Parmley in undergrad.

      Reply

  14. Taylor Poland
    Sep 07, 2022 @ 15:31:29

    To interpret a raw score, a professional may use either a criterion/ domain-referenced or norm-referenced instruments. The major difference between these two instruments is regarding what the scores are being compared to. A criteria or domain-referenced instrument compares a raw score with an established standard or criteria. The interest of this test is to see how the individual performs in relation to a previously established standard in place. An example of criterion-referenced instruments is in order to receive an A in a class, one must achieve a 90% or higher. The other type is norm-referenced instruments that compare a raw score to another score from individuals who have taken the same assessment. An example of this kind of test is the SAT or ACT.
    It is important to know the difference between criterion-referenced and norm-referenced instruments because the information is used in different ways. For criterion-referenced tests, one must meet or exceed a standard in place to pass. With norm-referenced tests, there is not a standard in place for one to pass or fail. A 50% in one test may mean something totally different in the other type of test so it is important to have a basic understanding of the two.
    I would say that I have a decent general understanding of a normal distribution. I feel more confident after rereading the section over. Some aspects were like a review, such as the fact that normal distributions are bell shaped curves and are symmetrical. The Z scores make sense but the T scores are a bit fuzzy. Hopefully with the help of class lecture and practice problems, I will gain more confidence.

    Reply

    • Abby Sproles
      Sep 07, 2022 @ 21:36:33

      Hi Taylor! Your explanation of the importance knowing the difference between the two instruments is very clear and it made me think in a different perspective! I initially thought that it is important in order to ensure you are giving an accurate explanation of the results, but expand on how a score for one test means something completely different for the other. Also, one test has a demarcation for mastery while the other doesn’t.

      Reply

    • Ashley Millett
      Sep 09, 2022 @ 17:52:06

      Hi Taylor,

      I find your explanations between the two instruments to be extremely helpful. I like how your answers were clear and in depth. It definitely helped me understand it a little bit better. I also find your examples from real life situations to be helpful in knowing which is which. I would also have to agree with you that with more review, it would become better to understand.

      Reply

  15. Ashley Millett
    Sep 07, 2022 @ 19:52:10

    Norm-referenced instruments would be used to take an individual’s score and compare that score to others who have also taken the same instrument. An individual’s score can be compared to the “norming group”. This norming group can either be large such as 2,000 people or small such as a classroom of 20 students. When someone takes an instrument, their score will then be compared to their norming group. They then will compare each individual’s scores that are within the norming group. Criterion-referenced instruments have the same agenda as norm-referenced but use comparisons differently. While norm referenced compares individual scores to others, criterion-referenced compares that score with standard/criterion. Criterion-referenced instruments are being used to see how the individual performs within the respect of a standard unlike norm-referenced instruments. A criterion-referenced instrument shows if the person had reached a certain standard of performance. It is important to understand the difference because these instruments have different outcomes and show different results. If you administer a test showing one thing and you interpret the results in another way, then the test is no good. If a test is no good, then everything else might crumble. The client will not have adequate treatment and care. It might cause more damage to the client than good if you do not distinguish between the two instruments.

    Normal distribution is slowly coming back to me. I have seen this before in both undergrad and also high school. I know how to calculate mean, median, mode and range along with standard deviation. When rereading the section, knowing how to calculate both T scores and Z scores slowly started coming back to me. However, knowing the bell curve and if a score is above or below the standard deviation might be a little confusing for me. I would definitely love a refresher during lecture so I know I am going in the right direction.

    Reply

    • Vic White
      Sep 09, 2022 @ 14:01:28

      Hi Ashley!

      I like how you explained that context is important by giving a real life example and then linked it to a counselling setting and situation.
      I did a lot of stats in ungrad but it’s been a couple years since then so I can definitely agree that reading the chapter was a nice refresher and it brought back a lot of my knowledge.
      Going through the standard deviations and percentiles in class yesterday helped with my understanding so now it’s just the T and Z scores I need to focus my attention on!

      Reply

    • Stephanie Lugo
      Sep 10, 2022 @ 17:29:38

      Hi Ashley,

      I think you did a great job explain the difference between Criterion referenced instruments and Norm Referenced Instruments. I like how you explained that Norm Referenced Instruments groups can be any size. In the case of using Norm Referenced Instruments there is no exact size needed as this particular system relies solely on individual scores and it does not use comparison or average scoring systems like Criterion referenced instruments does. I also agree with you about needing a refresher on some of the bell curve aspects of normal distribution.

      Reply

  16. Maria Nowak
    Sep 07, 2022 @ 21:17:22

    A norm-referenced instrument is one in which a single individual’s score is compared to other individuals who used the same instrument. For example, when a person takes the standardized test to get into the firefighter academy, their score is compared to everyone’s score who took that same exam. This is how they determine who to select to join the academy. Criterion/ domain-referenced instruments are those in which an individual’s score is compared to a general standard. For example, in high school we are required to take MCAS. This is a standardized test in which students are ranked on their performance in different subjects. There are 4 categories that a student can be ranked including failing, needs improvement, proficient, and advanced. In this case the individual student is being evaluated on whether they meet the standard score for each subject they are tested on.
    It is important to understand the difference between norm-referenced instruments and criterion/domain-referenced instruments because each serves a separate purpose on evaluation of an individual. For example, if you are using a norm-referenced instrument, the results of this only compare an individual’s score to other individuals scores. In this case it is not allowing you to gain insight on if a person has met a general standard. This is a useful tool if someone is wanting to simply compare a person to others. In contrast, when using a criterion/domain- referenced instrument it will allow the evaluator to see if an individual has mastered a specific area. If someone was solely comparing an individual to others it would not be adequate enough to get that specific information.
    My understanding of the normal distribution is that it is able to be used when scores fall into a normal range. For example, if you are using a normal distribution on a large population, you are more likely to be able to use a normal distribution as most of the time the bulk of the results will fall in the average range and slowly fade above and below the average. Though, it would be more difficult to use a normal distribution on a smaller population because it is less likely that the bulk of the scores will be average and fade out. There will likely be more outliers and the distribution will either be positively or negatively skewed.

    Reply

    • Grace Ling
      Sep 07, 2022 @ 22:56:29

      Hi Maria! I really liked the two examples that you used to further explain your definitions of norm-referenced and criterion-referenced instruments. I did not realize that firefighters were scored like that.
      I agree with your statement regarding the importance of understanding each instrument. In using these instruments, we are trying to learn different things based on interpretations of scores.

      Reply

  17. Rena Yaghmour
    Sep 07, 2022 @ 21:59:56

    Criterion/domain referenced instruments is to analyze how an individual’s performance was and compare it to a scale of some sort depending on what they are being tested on. Norm-referenced instrument refers to an individual’s performance that is then compared to another person’s performance all based around the same instrument.
    It is important to understand the difference between the two because their scales measure differently. It’s also important to note that a criterion/domain instrument tests individuals to see how they scored on a specific scale. For example, if someone does poorly on their driving test, they will most likely fail the test. With that being said they weren’t able to reach the standard criteria for that performance leaving them with no passing grade or approval to get their license. As for a Norm-referenced instrument there’s more leniency in scoring considering an individual performance is being compared to someone else’s. For example, if someone ran faster than another person that doesn’t mean the person who ran slower failed, it just means they had different times in which they can compare the two.
    My understanding for normal distribution is fairly basic, I get everything that has to do with mean, median, range, and mode. I also understand a little how it is a bell cure. However, I’m still shaky when it comes to standard deviation, T score and z score. Those I am definitely going to need some more clarification on.

    Reply

    • Megan VanDyke
      Sep 08, 2022 @ 11:04:02

      Hey, Rena! I like how when you gave an example for norm-referenced individuals, you emphasized that the slower runner did not fail. I did not originally compare the two instruments as such, so I appreciate you pointing that out. I’m also struggling a bit with the two different scores and standard deviation.

      Reply

    • Taylor Poland
      Sep 09, 2022 @ 09:52:34

      Hey Rena! The way you explained why it is important to understand the difference between the two instruments was really helpful. The examples provided for both crtierion-referenced and norm-referenced instruments made sense and emphasized the difference. One will either pass or fail a drivers test due to standards in place, whereas in a race, one person wins and the other loses as their times are compared to one another. Thanks for sharing that example- I feel like I have a better grasp of the material now!

      Reply

    • Maria Nowak
      Sep 10, 2022 @ 14:53:04

      Hi Rena!
      Your example on a norm-referenced instrument worked really well for this discussion. When you compared two runners and explained how the slower runner did not fail, it is important because when using an instrument like this it’s not a pass or fail like we would in a class. It is simply to compare an individual’s score to another person. Although, I would argue that in a norm referenced instrument its not necessarily giving more leniency. It’s more of just producing different information. For example, if you are measuring a single score compared to other scores from the same instrument, it is still telling us that the lower single score did not do as great as the others. Though, it still does depend on the context of what you are using the instrument for!
      Overall, great discussion!

      Reply

    • Stephanie Lugo
      Sep 10, 2022 @ 20:05:04

      Hi Rena,

      I think you did a great job describing both Criterion referenced instruments and Norm Referenced Instruments. I really like how you decided to use someones speed of running to explain how Norm Referenced Instruments are used. I would not have thought to use that as an example, but it ends up explaining Norm Referenced Instruments really well. I also agree that a refresher on Z-scores and T-scores would be very helpful.

      Reply

  18. Grace Ling
    Sep 07, 2022 @ 22:49:06

    Norm-referenced instruments compare scores with other individual’s scores from a standard sample (specific group of people used to create the instrument), whereas criterion/domain-referenced instruments compare scores with a certain standard. The standard for criterion-referenced instruments shows the level of mastery someone has over the test subject or subjects. An example of a norm-referenced instrument is how the MCAT (test to get into med school) is scored. After completing the MCAT, test takers receive their percentile which shows how they scored compared to other test takers. It is important to differentiate between these instruments because they are ultimately used for different situations/contexts. The score of one instrument does not necessarily line up with the score of another instrument.

    In terms of understanding normal distributions, I remember learning about all the different types of distributions from an intro biology course but normal distributions illustrate the average scores of a population. The middle of the bell curve shows the mean of the population and the two ends of the curve show outliers to the average. The normal distribution also shows us the range of scores within a population. When it comes to t-scores and z-scores, it has honestly been a long time since I last thought about those (there has been a whole pandemic since I last took stats 1). But from what I remember z-scores and t-scores tell you how many standard deviations you are from the average in a distribution.

    Reply

    • mikayladebois
      Sep 08, 2022 @ 08:31:38

      Hi Grace, I find it interesting that your first experience with normal distribution came from a biology course! I would think that something like medical school would want a criterion-referenced instrument because the best among a certain group might not be good at something, they’re just better than other people. I hope there is a shift at some point in the medical field where they no longer just compare the testers, they have to reach a certain level of mastery.

      Reply

  19. Ariannah Zagabe
    Sep 08, 2022 @ 00:34:21

    The difference between criterion/domain-referenced instruments and norm-referenced instruments is how the scores are dealt with. For Criterion/Domain-referenced instruments, the scores are set to specific/set standard (for example a driving/road test because you either pass or fail) while for Norm-referenced instruments, the scores of the participants are compared with each other for a specific group or category (for example standardized testing like the SAT where the results are compared to a percentile). It is important to know the difference between the two instruments to be able to precisely assess and interpret the results depending on what kind of assessment is being done.

    I don’t remember much about Normal Distribution from the past and find it confusing. What I do know about Normal Distribution is that it is bell shaped/symmetrical and the mean/median/mode are equal. My understanding is pretty vague, and I’ll need to refresh the topic because I don’t remember much about it.

    Reply

    • Gitte Lenaerts
      Sep 08, 2022 @ 16:22:34

      Hi Ariannah! You did a great job explaining the difference between criterion and norm-referenced instruments. With this topic, I find that having examples is really important. I also used the example of the driving test for criterion-referenced instruments, as it is a common test that most people have taken! As for the normal distribution, it was confusing at first and though I have learned about it in previous classes before, I still get hung up. But like you mentioned, the normal curve, is what I try to think about regarding the normal distribution. That is what the “ideal” distribution would look like.

      Reply

    • Megan VanDyke
      Sep 09, 2022 @ 07:24:11

      Hey, Ariannah! I’m not sure how to calculate scores into a bell curve but from my understanding, a bell curve visually distributes a set of scores. In the middle should be most of them, as that is where the peak is. Using your SAT example, if the average test score is about 1050, you would see 1050 in the middle of the x-axis under the peak of the curve. 1050 would also be the mean, median, and mode of the distribution. If I’m wrong, someone please reply and correct me.

      Reply

  20. Melissa Elder
    Sep 08, 2022 @ 07:08:44

    Norm-referenced instruments are a comparison of two separate individuals score on the same instrument. For example a norming group could be as large as 2,000 individuals or as small as a typical class size, but the scores are all always being compared with one another. Criterion/domain-referenced instruments is an individuals score compared to an established standard designed to measure performance within one particular domain. For example this would be a pass or fail , A specific grade is needed to be obtained in order to prove an individual has attained an established level of mastery for the particular domain.
    The main difference between the two instruments is that norm-referenced instruments is being compared to other individuals taking the same instrument, while criterion/domain-referenced instruments is testing an individual on what they know and has a predetermined cutoff score making it pass or fail. Both of these would be used in very different situations so it would be important to know which instrument is appropriate to use in particular situations.
    I know Normal distribution is connected to the ‘bell curve’ which show that the data near the mean are way more frequent compared to the data farther from the mean. I know that normal distribution is used along side mean, median, mode, standard deviations etc and I also know that normal distribution assists in the interpretation of norm-referenced instruments.I want to say I understand normal distribution but I feel like I’m still not 100% positive on fully understanding, I would not say it is confusion I would just say I need a good refresher.

    Reply

    • Emily Forde
      Sep 08, 2022 @ 10:17:45

      Hi Melissa! When thinking of the criterion-referenced instruments I also thought of the grading system and the presence of a pass/fail system. I think this is a good way to visualize this instrument by seeing it in a real life example that we encounter all the time. Do you feel like there are different levels of passing or failing in the criterion-referenced instrument? The ‘master level’ idea that is involved in this instrument makes me think that their may be levels of passing and failing in this system.

      Reply

  21. Wendy Fernandes
    Sep 08, 2022 @ 10:12:38

    Norm referenced instruments compare the score of an individual to the scores of others who have used that same instrument. The instrument is administered to many participants who make up the norming group and the score of the individual is assessed against the scores of all the other participants. The scoring in these assessments usually include a percentile ranking that compares the individuals score to others who have used the same assessment. Commonly known norm referenced instruments are tests used in education such as the SAT, GRE, or IQ tests. When interpreting these instruments, it is important to note that the instrument measures how much an individual knows compared to others who have taken the same test and the raw scores are adjusted to account for the relative difficulty of the test.

    With criterion or domain referenced instruments the individual earns a score based on their knowledge of the subject matter and is not compared to others who have used that same instrument. Examples of this include spelling tests, or in the case of professional licensing how well an individual knows about that specific subject matter. With criterion referenced instruments there may be a level of mastery of the content that needs to be achieved to move on to the next level of learning or to complete the program.

    The main difference between these two instruments is the way that they are scored. For example, with a norm referenced instrument it is possible to answer 80% of the test questions correctly but rank in the 70th or 90th percentile depending on how the questions on the test are weighted and the answers of others who make up the grouping norm, while with criterion referenced instruments if 80% of the questions were answered correctly then the grade would be 80%.

    It is important to know the differences between norm referenced and criterion referenced instruments because they each provide different sorts of information. For instance, in future when we are administering certain types of psychological tests it will be relevant for us to know the percentile ranking our client has on an assessment that determines the level of depression versus taking a test on their knowledge of depression.

    I feel comfortable with my general understanding of the normal distribution, mean, median, and mode as well as they various types of graphs. The one area mentioned in the lecture that I will have to take some time with is memorizing the percentages that correspond to the standard deviations (one standard deviation is 34.13% away from the mean, from one standard deviation to two standard deviations is 13.59%, etc).

    Reply

    • Chandal Powell
      Sep 09, 2022 @ 22:53:57

      Hi Wendy,
      I found your explanations about norm referenced and criterion referenced instruments quite easy to follow especially with the example given . I love how you tied the explanation of the main difference between both norm referenced and criterion referenced instruments to its relevance to us when we begin administering different assessments. It helps to solidify the connection to what we’re learning and how we will utilize it in the future.

      Reply

    • Ariannah Zagabe
      Sep 10, 2022 @ 11:16:48

      Hi Wendy,
      I liked how you gave a thorough/in depth description about the difference between norm-referenced instruments and criterion-referenced instruments. I also liked how you mentioned that it’s important to note that when interpreting norm-referenced instruments
      it measures how much an individual knows compared to those who have also taken that test and the scores are adjusted to account for the relative difficulty of the test.

      Reply

  22. Emily Forde
    Sep 08, 2022 @ 10:12:51

    Norm-referenced instruments utilize the scores of others who have taken the same instrument in order to understand the meaning of an individual’s score. The ‘norm’ is the group that took the same instrument and whose scores are being used as a tool for score analysis. This instrument focuses on how the individual being measured compares to other individuals who were measured in the same way. On the other hand, criterion-referenced instruments focus on comparing the individual’s score to an established standard. These kinds of tests focus on if the person reaches a standard, and if so they may be considered for a mastery component. Individuals who score highly based off the established standard are considered to be at the mastery level.
    It is important to understand the difference between these two instruments because the results give different meaning based off how they were measured. The results of a norm-referenced instrument will tell you how the individual compares to others. The results of a criterion-referenced instrument will tell you if an individual has skill and at what level they have that skill, whether they are basic or mastery for example. It is also important to understand the difference because some testing materials may be more applicable for one instrument rather than another. For example, if you were observing an child’s social skills you would likely want to use a norm-referenced instrument in order to measure their social skills in relation to other children their age because social skills typically differ based on age.
    I understand the normal distribution to be an ‘ideal’ data distribution. In this distribution, the majority of people fall in the middle of the bell curve and a small percent of people fall on the sides of the bell curve. Something that was a little confusing to me was the stanine scale.

    Reply

    • Wendy Fernandes
      Sep 09, 2022 @ 22:12:13

      Hi Emily!
      I found your explanations about norm referenced and criterion referenced instruments easy to follow and concise. I especially liked your example about observing children compared to others of a similar age and using norm referenced instruments. I do not even think there could be a criterion-based instrument for this, but that raw score would not matter as much as being able to rank the child’s social skill to others in that norming group. Nice post!

      Reply

  23. Vic White
    Sep 08, 2022 @ 12:56:53

    The main difference between norm-referenced instruments and criterion referenced instruments is what the scores are compared to. Norm referenced compares an individuals score against other individuals. The “norm” is a group of people in which have taken the instrument and other individuals will then be compared too. There is a focus on how an individual does based on how others do. However, in criterion referenced instruments individual scores are compared against a criterion that is already set in place. In contrast to norm referenced, the focus here is to compare individuals to a standard. There is also the inclusion of a mastery component which is what we would all have had an experience with – whether it be passing your driving test, passing an exam. This component has a cut off score which is a minimum score the person needs to achieve mastery which the norm references instruments do not have.
    Its important to understand the difference between the instruments because they are both used in different ways. As mentioned before, the criterion referenced instruments are how you would grade a paper, or it determines whether you have passed your driving tests (or any other test come to think of it), where as norm-referenced instruments can not be used for the same. Norm referenced instruments are better adapted and used for measuring heights, weights and IQ amongst individuals.

    A normal distribution is an ideal set of results you would want to achieve, this is because a normal curve has more benefits when it comes to interpreting the data especially for norm-referenced instruments. Normal distribution means that the majority of scores are in a cluster around the mode and median point. On a graph it presents itself as a bell-shaped curve, which is symmetrical, and it reflects that the majority of scores fall in the middle range (within 1 standard deviation below and 1 standard deviation above the mean). As you move to 2 standard deviations and 3 standard deviations away from the mean, the numbers decrease on each side of the curve, with the smallest amount of people being in 3 standard deviations. In regard to percentiles and normal distribution, that’s something that I need to read more on and gain a better understanding, I feel like I understand it at base knowledge but then numbers get introduced and I seem to get caught up in it.

    Reply

    • Gitte Lenaerts
      Sep 08, 2022 @ 16:15:01

      Hi Vic! When learning about norm-referenced and criterion-referenced instruments, coming up with examples made it helpful for me. I also used the example of a driving test for criterion-referenced instruments! Having examples with each instrument made it easier for me to retain and see the differences between tests. I also stated in my discussion that I needed a review on percentiles. Similarly, I also know percentiles at base knowledge once needing to use them or refer to them, I get caught up as well. Great post!

      Reply

  24. Alysha Benoit
    Sep 08, 2022 @ 16:38:28

    1. To put the difference between criterion/domain-referenced instruments and norm-referenced instruments in my own words, a criterion/domain-referenced instrument can be described as similar to an instrument used to measure if an individual reaches or passes a certain “check-point”. Similar to measuring whether someone is eligible for a raise at their job, they may take various courses or quizzes to ensure that they meet the standards for the raise and/or intensified occupational tasks. In psychological assessments, criterion/domain-referenced instruments can evaluate and determine whether a client is ready to move-on/away from therapy or whether they may need more time with a therapeutic intervention. If the client is assessed based on these principles and they reach the “check-point” of that domain (the domain being the effectiveness of an intervention), they are then referred out of therapy in that the therapeutic intervention was effective. Norm-referenced instruments can be described as instruments that are used to compare an individual’s assessment scores or outcomes to a group similar to them or a group that they are a part of. To relate back to an occupational example, an individual’s performance on certain courses or quizzes related to their job would be compared to other employees within the same occupation. The scores of each employee can be used to determine or assess who would be awarded as employee of the month or whether management is successfully training and supervising their employees.

    2. The normal distribution or normal curve is something that I have been familiar with since middle school, so it makes a decent amount of sense to me. I remember my seventh grade science teacher explaining this distribution in terms of a “bell-curve” in which most teachers and school administrators use to explain grade averages on homework and exams. In this reference, the majority of students will most likely fall into the higher points of the bell (students receiving about a C+) and fewer students will land in the outer left and right areas of the bell-curve shape (students receiving either A’s and B’s or C’s and below). As the text describes, this normal curvature is widely used in interpreting scores of norm-referenced instruments such as student’s grade scores in a particular class.

    Reply

    • Chandal Powell
      Sep 09, 2022 @ 23:03:55

      Hi Alysha,
      I love the example that you used as it relates to therapy and therapeutic interventions. This helps me at least to see the connection between what we are learning and in the future will apply. I appreciate the way in which you explained normal distribution as its easily understood. This has been helpful for me as I stated in my discussion I needed a refresher on a few things.

      Reply

  25. Magdalen Paul
    Sep 08, 2022 @ 16:44:44

    Norm-referenced instruments involve comparing an individual’s score with those scores of other individuals who have taken the same instrument. In this way, the point of comparison for one’s score is the performance of other people. This is different from criterion/domain-referenced instruments in that an individual’s score is compared with an established standard that is not influenced by the performance of its “takers.” In other words, criterion/domain-referenced instruments do not involve comparing one’s score to the score of others—rather, one’s score is compared to a pre-set domain (that often indicates “mastery”). Knowing the difference is important because both instruments measure very different things and, in choosing an instrument or interpreting an instrument’s results, counselors must be able to determine which is appropriate, and why. Want to know how well a student did on a test compared to the rest of the class (how much better he/she did than other students)? Norm-referenced. Want to know how well a student understood the test material? Criterion/domain-referenced.

    The normal distribution makes sense in that, as a sample becomes larger and more representative of a population, most data points / values (traits, scores, etc) would fall around the same general area, and the more rare data points, being rare, would be lesser and therefore skew off towards the tail ends of the curve. But I can always use more explanation, practice and clarification!

    Reply

    • Melissa Elder
      Sep 09, 2022 @ 11:42:54

      Maggie,
      I really like the questions you put in regards to why you would use norm reference compared to criterion/domain reference instrument, that gave a really good example of the difference between the two and helps clear up any confusion. I also liked how you described normal distribution I thought it may be important to add that it is perfectly symmetrical so the right side is a mirror image of the left side. I would agree it is always nice to get a refresher on subjects such as these, I took my statistics class my Freshman year so it has been a while!!

      Reply

    • Maria Nowak
      Sep 10, 2022 @ 15:00:48

      Hi Maggie!
      I really liked the way you explained the difference between the two instruments. Specifically, it is important how you mentioned how counselors must be able to determine which instrument is appropriate to use. This is important as each instrument is producing different comparisons. A norm-referenced instrument could maybe be more beneficial when assessing a large population and seeing how well students have done as a whole. This would also be able to identify what areas need to be taught more. In contrast, a criterion/domain referenced instrument is beneficial for seeing a single individual’s results.
      Great discussion post!

      Reply

  26. Brenna Stewart
    Sep 08, 2022 @ 17:29:15

    1. Criterion/domain-referenced instruments specifically refer to an already-established, widely-known “criteria”. An example of this includes a driver’s test. There are set criteria for passing a driver’s test that each person needs to meet in order to pass. Norm-referenced instruments are measured based on the comparison of others’ scores on the same instrument, rather than a universal criteria. Since the textbook took all the examples I could think of.. I’ll try to get creative and say that if a driver’s test was measured using a norm-referenced instrument, each score would be measured based on the statistics of pass/fail rates. Both instruments interpret results differently so it’s important to be able to understand the difference especially depending on what evidence/results you are searching for.

    2. Normal distribution feels like both a simple and complex concept.. I understand it and also get confused with it at the same time. I understand how it is a highly useful tool for norm-referenced instruments, as the normal curve gives a solid comparison of who falls within the majority and who doesn’t (more accurate for larger samples, less accurate for smaller).

    Reply

    • Vic White
      Sep 09, 2022 @ 14:14:01

      I like that you were creative and went for an example not in the book! I would say that another difference between the two are that the criterion referenced instrument has the mastery component which is something that the norm-referenced does not. I think remembering the mastery component gives a better understanding on where it is suitable to use the criterion instruments; either passing or failing the licensing exam.

      I agree about the normal distribution! Sometimes I think I over complicate it and end up getting myself confused instead of sticking to the basics and just looking at what it right in front of me. I also really like your point about the sample size having an impact on the accuracy of the graph. That is something I hadn’t given much thought into!

      Reply

Leave a Reply to Jack Halliday Cancel reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

Adam M. Volungis, PhD, LMHC

Enter your email address to subscribe to this blog and receive notifications of new posts by email.

Join 88 other followers
%d bloggers like this: