Psychological Assessment Lecture - Validity and Reliability PDF

PSYCHOLOGICAL ASSESSMENT LECTURE Lesson 4 Part 1: WHAT IS A GOOD TEST? VALIDITY CLEAR INSTRUCTION →​ A good test should have well-defined instructions for ❖​ VALIDITY AS ESSENTIA...

PSYCHOLOGICAL ASSESSMENT LECTURE Lesson 4 Part 1: WHAT IS A GOOD TEST? VALIDITY CLEAR INSTRUCTION →​ A good test should have well-defined instructions for ❖​ VALIDITY AS ESSENTIAL. A test is considered valid if it how it is administered, scored, and interpreted, ensuring genuinely measures what it claims to measure. consistency and fairness in the assessment process. →​ e.g., A scale that consistently measures a 1-pound gold bar as weighing 1 pound is considered valid. MEASUREMENT ACCURACY →​ The most crucial criterion for a good test is its ability ❖​ CONTROVERSY IN VALIDITY. While concepts like to accurately measure what it claims to measure. This reaction time have clear definitions, validity becomes ensures that the test provides meaningful and reliable contentious in areas like intelligence due to varying results. definitions. Tests claiming to measure these constructs are closely scrutinized for validity. TECHNICAL CRITERIA →​ In addition to logical criteria, assessment professionals ❖​ DEFINITION OF INTELLIGENCE. The controversy use technical standards to evaluate test quality. around intelligence’s definition impacts the validity of tests measuring it. If a test’s definition differs significantly PSYCHOMETRIC SOUNDNESS from widely accepted definitions, it may be criticized →​ Test users often refer to the psychometric soundness for lacking validity. of tests, which involves the rigorous application of measurement principles and statistics analysis to ❖​ VALIDITY QUESTIONS FOCUS. Questions about a ensure the test’s quality and reliability. test’s validity may center on its items. Are they representative of the construct being measured? Individual RELIABILITY items also undergo scrutiny regarding their contribution to →​ Reliability is a key aspect of psychometric soundness, or detraction from test validity. which indicates the consistency and stability of the test’s results over time and across different ❖​ INTERPRETATION OF TEST SCORES. Validity inquiries test-takers. A good test should yield consistent results. extend to interpreting test scores. Critics may ask what the scores truly reveal about the measured construct, VALIDITY how high scores in this test correlate with scores on →​ Validity is another critical element of psychometric similar or opposing constructs. soundness, which ensures that the test actually measures what it intends to measure. A good test ❖​ RELATIONSHIP BETWEEN TESTS. Validity can involve should be valid, meaning it accurately assesses the examining how scores on one valid test relate to scores on intended construct or trait. another measuring the same or opposing constructs. →​ e.g., Scores on a valid introversion test might inversely correlate with scores on a valid extraversion test. RELIABILITY ❖​ ONGOING VALIDITY ASSESSMENT. Questions ❖​ RELIABILITY AS A KEY CRITERION. A good measuring regarding a test’s validity can arise at various stages, tool or procedure must possess reliability, which from its initial development to its use with different pertains to the tool’s consistency and precision in populations. measurement, as well as the extent of measurement ❖​ Assessment professionals continuously evaluate error. whether a test accurately measures what it claims to measure. ❖​ PERFECT RELIABILITY. Theoretically, a perfectly reliable measuring tool consistently provides the same ❖​ Examples with Scales: Construct Validity measurement results with precision and without error. →​ MMPI-2 includes scales measuring constructs like depression, anxiety, and psychopathy, which align ❖​ Examples with Scales: Test-Retest Reliability with established psychological theories. →​ If an individual takes the WAIS-IV today and retakes it →​ Demonstrate that the MMPI-2 measures the intended after a few weeks or months (assuming no significant constructs based on strong correlations with similar tests changes in cognitive abilities), their IQ score should →​ e.g., Beck Depression Inventory for depressive symptoms remain consistent. →​ e.g., A person scores 115 on the first administration and 116 on the second, indicating strong test-retest reliability. OTHER CONSIDERATIONS ❖​ IMPORTANCE OF RELIABILITY. Unreliable ❖​ EASE OF ADMINISTRATION, SCORING, AND measurement is undesirable. A reliable measuring tool INTERPRETATION. A good test should be user-friendly, yields consistent results when measuring the same allowing trained examiners to administer, score, and thing under the same conditions. interpret it with minimal difficulty. ❖​ PSYCHOLOGICAL TESTS AND RELIABILITY. ❖​ USEFULNESS AND ACTIONABLE RESULTS. A good Psychological tests, like other measurement instruments, test is not only easy to use but also yields actionable vary in terms of reliability. It is crucial for these tests to results that can benefit individual test takers or society as demonstrate reliability, but reliability alone is not a whole. sufficient for a good test. ❖​ EVALUATION OF TEST QUALITY. There are various ways to assess the quality of a test. ❖​ ROLE OF NORMS. Norms are standards that provide a reference point for evaluating test results. They help contextualize it to the performance of a larger group.