Podcast
Questions and Answers
What is a reliability coefficient?
What is a reliability coefficient?
A reliability coefficient is a proportion that indicates the ratio between the true score variance on a test and the total variance.
What are the two main types of error variance?
What are the two main types of error variance?
The two main types of error variance are true variance and error variance.
Which of these factors contribute to error variance in test construction?
Which of these factors contribute to error variance in test construction?
Which of these factors contribute to error variance during test administration?
Which of these factors contribute to error variance during test administration?
Signup and view all the answers
Which of the following factors contribute to error variance during test scoring?
Which of the following factors contribute to error variance during test scoring?
Signup and view all the answers
Which of these is NOT a type of reliability estimate?
Which of these is NOT a type of reliability estimate?
Signup and view all the answers
What are two types of internal consistency reliability estimates?
What are two types of internal consistency reliability estimates?
Signup and view all the answers
The Spearman-Brown formula allows a test developer to estimate internal consistency reliability from a correlation of two halves of a test.
The Spearman-Brown formula allows a test developer to estimate internal consistency reliability from a correlation of two halves of a test.
Signup and view all the answers
The Kuder-Richardson Formula 20 is a preferred statistic for obtaining an estimate of internal consistency reliability when items are homogeneous.
The Kuder-Richardson Formula 20 is a preferred statistic for obtaining an estimate of internal consistency reliability when items are homogeneous.
Signup and view all the answers
Which of the following is NOT a type of construct validity?
Which of the following is NOT a type of construct validity?
Signup and view all the answers
A validity coefficient measures the relationship between test scores and scores on the criterion measure.
A validity coefficient measures the relationship between test scores and scores on the criterion measure.
Signup and view all the answers
A reliable test is always a valid test.
A reliable test is always a valid test.
Signup and view all the answers
Study Notes
Chapter III: Introduction
- This chapter introduces the concepts of reliability and validity in psychological testing.
- It uses a narrative example of a person being robbed to illustrate the importance of reliability in a trustworthy relationship.
Reliability and Validity in Psychological Testing
- Reliability refers to the consistency of a measure.
- Validity refers to the accuracy of a measure.
- A reliable measure is consistent, while a valid measure accurately measures what it is intended to measure.
- Reliability and validity are important properties of a psychological test.
Reliability Coefficients
- Reliability coefficients are a ratio of true variance to total variance.
- The greater the proportion of true variance, the more reliable the test.
Sources of Error Variance
- Test Construction: The extent to which the test samples the content being measured.
- Test Administration: The test environment (e.g. temperature, noise) and test-taker variables (e.g., stress, fatigue).
- Test Scoring and Interpretation: Subjectivity in scoring, scoring systems, and rater bias.
Types of Reliability Estimates
- Test-retest reliability: Scores are consistent over time.
- Parallel forms reliability: Equivalent forms of the test produce similar results.
- Internal consistency reliability: Different items on a scale measure the same construct. (Split-half reliability, Cronbach's alpha, KR-20 & KR-21)
True Score Model of Measurement
- Classical test theory assumes a true score exists for a person's ability, but measurement error is inevitable.
- Observed score = True score + Error.
Item Response Theory (IRT)
- Modern approach that focuses on the difficulty of individual items on a test.
- Item difficulty is crucial in assessing an individual's level of ability.
- Computer adaptive tests utilize item response theory.
Validity
- Validity assesses if a test measures what it is intended to measure.
- Three main types of validity evidence:
- Content validity (sample of the concept/content)
- Criterion validity (predicting a future outcome or comparing to a similar measure)
- Construct validity (theories of constructs; tests measuring the quality of theories)
- There are several subtypes of these evidence types.
- Face validity is the perceived validity of a test.
Validity Coefficient
- A correlation coefficient that measures the relationship between test scores and criterion scores.
- High validity coefficients, generally, suggest a strong relationship.
Inter-Scorer Reliability (Kappa Statistics)
- Assessing the agreement between multiple scorers on the test.
- This can be influenced by sources such as Time, sampling, items, and internal consistency.
Important Considerations
- Reliability is necessary but not sufficient for validity.
- A reliable test can be invalid.
- Validity is context specific
- High reliability is essential in clinical contexts where important decisions are made.
- Estimates of reliability usually range from 0.70 to 0.80 for most purposes.
How Reliable Is Reliable?
- The answer depends on the context and purpose of the use of the test.
- Reliabilities above 0.95 are not particularly useful.
- Reliability is essential in cases involving important decisions and classifications.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
This chapter covers key concepts in psychological testing, focusing on reliability and validity. It emphasizes the significance of these concepts using a narrative example to illustrate how reliability impacts trust in relationships. Understanding these principles is essential for evaluating psychological assessments.
