Free Psychometrics Theoretical Foundations Questions and Answers — Questions and Answers
Question 1: What is the main focus of Classical Test Theory (CTT)?
- Relationship between test items and latent traits
- Observed scores, true scores, and error (Correct answer)
- Performance differences among groups
- Assessing cultural bias in testing
Correct answer: Observed scores, true scores, and error
Classical Test Theory (CTT) is a foundational psychometric theory that focuses on the relationship between an observed score, a true score, and measurement error. CTT posits that an observed score on a test is composed of a true score (the actual, unobservable ability or trait) and random error. Its main goal is to estimate the reliability of a test and the precision of its measurements.
Question 2: What is a latent trait in psychometrics?
- A measurable physical characteristic
- An observable behavior
- An underlying psychological construct inferred from data (Correct answer)
- A scoring system for test results
Correct answer: An underlying psychological construct inferred from data
In psychometrics, a latent trait (or latent variable) refers to an unobservable psychological construct or characteristic that is inferred from observable responses or behaviors. Examples include intelligence, anxiety, or conscientiousness. These traits cannot be directly measured but are hypothesized to underlie and explain patterns in test scores or other empirical data.
Question 3: Which psychometric theory emphasizes the probability of a specific response to a test item based on individual traits?
- Classical Test Theory (CTT)
- Item Response Theory (IRT) (Correct answer)
- Criterion-Referenced Testing
- Norm-Referenced Testing
Correct answer: Item Response Theory (IRT)
Item Response Theory (IRT) is a modern psychometric framework that models the relationship between an individual's latent trait level (e.g., ability) and the probability of them giving a certain response to a test item. Unlike Classical Test Theory, IRT focuses on individual item characteristics and how they interact with a test-taker's ability, providing more detailed insights into item functioning and test-taker performance.
Question 4: What is factor analysis used for in psychometrics?
- Reducing cultural bias in tests
- Exploring the structure of psychological constructs (Correct answer)
- Predicting future performance
- Measuring reliability over time
Correct answer: Exploring the structure of psychological constructs
Factor analysis is a statistical technique widely used in psychometrics to identify underlying dimensions or factors that explain the correlations among a set of observed variables. It helps researchers understand the structure of complex psychological constructs, such as personality or intelligence, by reducing a large number of observed variables into a smaller set of latent factors. This process reveals how different items or behaviors group together.
Question 5: What is a key assumption of Item Response Theory (IRT)?
- Test items are equally difficult for all test-takers.
- Test-taker responses depend on both item characteristics and individual traits. (Correct answer)
- Reliability and validity are irrelevant in test development.
- Every test-taker's true score is constant across different items.
Correct answer: Test-taker responses depend on both item characteristics and individual traits.
A key assumption of Item Response Theory (IRT) is that the probability of a test-taker answering an item correctly is a function of both the test-taker's underlying ability or trait level and the characteristics of the item itself (e.g., its difficulty and discrimination). This allows IRT to model how different individuals interact with different items, providing a more nuanced understanding of measurement than CTT.
Free Psychometrics Theoretical Foundations Questions and Answers
What is the main focus of Classical Test Theory (CTT)?