Intelligence & Psychological Testing

Intelligence & Psychological Testing

1. Key Concepts

   • Psychological test
     • A standardized measure of a sample o a person's behaviour
     • Mental ability tests remain the most common kind of test
       • Intelligence test
         • Measures general metal ability.
         • Aptitude test
           • Asses specific types of mental abilities such as verbal reasoning, numerical, and abstract reasoning
           • Achievement test
             • Test gauge a person's mastery and knowledge of various subjects such as reading, English, or history.
   • Personality test
     • Measures various aspects of personality including motives, interests, calues and attitudes.
     • Standardization & Norms
       • Standardization
         • Refers to the uniform proccedures used in the administration & scoring of a test.
         • Test norms
           • Provide information about where a score on a psychological test ranks in relation to other scores on that test.
           • Percentile score
             • Indicates the percentage of people who score at or below the score one has obtained.

2. Reliability

   • Refers to the measurement consistency of a test (or of other kinds of measurement techniques)
   • One widely used approach is to check test-retest reliability, which is estimated by comparing subject's scores on two administrations of a test
     • Correlation coefficient
       • A numerical index of the degree of relationship between two variables

3. Validity

   • Refers to the ability of a test to easure what it was designed to measure
   • Also used to refer to the accuracy or usefulness of the inferences or decisions based on a test
     • A specific test may be valid for one purpose, such as placing students in school, and invalid for another purpose such as making employment decisions for a particular occupation.

4. Content validity

   • Refers to the degree to which the content of a test is representative of the domain it's suppose to cover.

5. Criterion- Related Validity

   • Is estimated by correlating subject's scores ona test with their scores on an independent criterion (another measure) of the trait assessed by the test.

6. Construct Validity

   • The extent to which there is evidence that a test measures a particular hypothetical construct.
   • The on going debate about the construct validity of intelligence tests is one of the oldest debates in psychology

7. The Evolution

   • The first modern psychological tests were invented a little over a 100 years ago
   • Galton Studies of Hereditary Genius
     • Galton, 19th century, concluded that success runs in families because great intelligence is passed from generation to generation through genetic inheritance
   • Binets Breakthrough
     • The Binet-Simon scale expressed a child's score in terms of mental level, or mental age.
       • Mental age
         • Indicated that he/she displayed the mental ability typical of a child of that chronological age
   • Terman & Stanford- Binet
     • Intelligent quotient (IQ)
       • Is a child's mental age divided by chronological age, multiplied by 100.
   • Wechsler's Innovation
     • David Wechsler was charged with overseeing the psychological assessment of thousands of adult patients
       • Wechsler set out to improve on the measurement of intelligence of adults. He created the Wechsler Adult Intelligence Scale.
         • Less dependent on subject's verbal ability than the Stanford-Binet. Secondly, he favoured a new scoring scheme based on normal distribution

8. The Debate

   • Charles Spearman
     • factor analysis
       • Correlations among many variables are analyzed to identify closely related clusters of variables
   • Fluid intelligence
     • Involves reasoning ability, memory capacity, and speed of information processing
   • Crystallized intelligence
     • Involves the ability to apply acquired knowledge and skills in problem solving