The Scales We Use and the Comparisons We Make
Resources
Attributes and Evaluation of Discussion Contributions.
In this unit, you are introduced to four scales of measurement, which are easily remembered with the acronym NOIR, and include nominal, ordinal, interval, and ratio. Each of these levels or scales of measurement has its own properties, methods for assigning numbers or scores, and procedures for statistically manipulating them. As noted in your Psychological Testing and Assessment text, and adhering to a fundamentalist view of measurement statistics, all possible attributes in psychology can be examined through at least one of these four scales and the creation of scores that purport to measure them.

You also read about two methods for evaluating those scores through comparing them to a reference set of data; namely, norm-referenced testing and assessment, and criterion-referenced testing and assessment. Each of these methods is unique in the focus regarding a test’s scores or results.

Discuss the impact of each scale of measurement on the ability or inability to be utilized on a test being standardized as a norm-referenced or criterion-referenced assessment. For the purpose of this discussion, you may cluster the ordinal and interval scale together. Subsequently, your post will include the following four elements:

Ordinal or interval scale of measurement and norm-referenced test.
Ordinal or interval scale of measurement and criterion-referenced test.
Ratio scale of measurement and norm-referenced test.
Ratio scale of measurement and criterion-referenced test.
In you post:

Provide at least one example that is not in your Psychological Testing and Assessment text for each combination above and describe how the referencing data would be collected.
Provide a statement that evaluates which scale of measurement appears to be the most useful for examining attributes in psychology. Explain.
Evaluate which method of referencing (norm or criterion) appears to be the most useful for examining attributes in psychology. Explain your decision based on the area of focus regarding the test results. For example, identify if it is preferable to focus on how one individual performs relative to others who took the same test, or if it is preferable to only focus on what the individual can or cannot do.

Studies
Key Concepts
Review Unit 2 Key Concepts.

Readings
Use your Psychological Testing and Assessment: An Introduction to Tests and Measurement text to complete the following:

Read Chapter 3, “A Statistics Refresher,” pages 77–116.
Read pages 124–143 of Chapter 4, “Of Tests and Testing.”
Use your Standards for Educational and Psychological Testing text to read Chapter 5, “Scores, Scales, Norms, Score Linking, and Cut Scores,” pages 95–107.

Use the Internet to review page 5 of “Code of Fair Testing Practices in Education” from Joint Committee on Testing Practices.

View the document List of Tests by Type [PDF]. See the assignment instructions and the course project information.

Media
Complete the following:

Click Norm-Referenced Versus Criterion-Referenced Assessment to view the presentation.
Click Measurement Scales Activity​ to view the presentation.
Click Correlation to view the presentation.
Unit 2 Learning Check
Complete the Unit 2 Learning Check quiz. All learning checks are required activities. While you do not receive a unit grade for completing each check, it remains a course requirement, and will assist you in understanding the content in the units, as well as prepare you for the final quiz in Unit 10, which is graded.