Unit 13: Testing & Individual Differences
13.3 General Concepts in Testing
Definition of intelligence – generally defined as the ability to learn from experience, solve problems, and use knowledge to adapt to new situations
- Charles Spearman (1863-1945)– factor analysis – the “g” factor - Believed we have ONE GENERAL INTELLIGENCE – shortened to “g” factor to make it easier…or more confusing…the g factor underlies all intelligent behavior. Believed people had special abilities and Spearman developed FACTOR ANALYSIS to statistically identify clusters of related items – High verbal intelligence correlates highly with spatial reasoning - The idea of ONE score was controversial
- L.L. Thurstone (1887-1955) – Primary Mental Abilities -Opposed the one score idea of Spearman – he gave 56 tests to people and identified seven clusters of PRIMARY MENTAL ABILITIES - Thurstone helped develop the SAT (YOU'RE WELCOME). HOWEVER, despite Thurstone giving out multiple scores, meta-analysis of his scores showed that those who did well in one area did well in another area - evidence of a g factor?
PRIMARY MENTAL ABILITIES: Word fluency, Verbal comprehension, Spatial ability, Perceptual speed, Numerical ability, Inductive reasoning, Memory
- Cattell – fluid intelligence/crystalized Intelligence. Believed that multiple ways of assessing intelligence was more informative than a single g factor. Fluid intelligence involves reasoning ability, memory capacity, and speed of information processing. Crystallized intelligence involves ability to apply acquired knowledge and skills in problem solving.
- Gardner – Multiple Intelligences - NOT one g factor, but MULTIPLE ways of being intelligent - 8 ways. To gather these 8 ways Gardner studied those with normal intelligence, and those who were EXCEPTIONAL – brain damage, prodigies, savants – broad range of people. Critics of this theory point out that the broader you make the term intelligence the less it means, and also people do not necessarily HAVE a strength area of intelligence.
Logical-mathematical, Linguistic, Musical, Spatial, Bodily-kinesthetic, Interpersonal, Intrapersonal, naturalist
- Sternberg – Triarchic theory. Not 8, but rather 3 types of intelligence. ANALYTICAL (academic problem-solving) is assessed by intelligence tests, which present a well-defined problem with a single answer. Test like those predict school success well, vocational success less well; CREATIVE INTELLIGENCE – ability to react adaptively to novel situations and generate novel ideas; PRACTICAL INTELLIGENCE – required for everyday tasks, which are ill-defined, with multiple solutions
A Psychological Test is just a standardized measure of a SAMPLE of a person’s behavior – measure individual differences among people in their abilities, aptitudes, interests, and aspects of personality.
SAMPLING = CAUTION, not the whole story
Issues to Look Into When Deciding the Value of the Test
Standardization – refers to the uniform procedures used in the administration and scoring of a test. Needs to be the same instructions, questions, time limits, environment.
Norms – Norms provide information about where a score on a psychological test ranks in relation to other scores on that test. Psych test tell you where you score relative to other people.
- Percentile score – indicates the percentage of people who score at or below the score one has obtained.
- Standardization group – sample of people the norms are based on- needs to be representative of the whole population
Reliability (consistency) – the measurement consistency of a test
- Test-Retest reliability – estimated by comparing subject’s scores on TWO administrations of the SAME test
- Test-retest reliability relies on being able to figure out CORRELATIONAL COEFFICIENTS – numerical indices of the degree of relationship between two variables
Other measures of RELIABILITY
- Alternate-forms reliability - authenticity stablished by carrying out two different forms of the same test to the same individuals
- Split-half reliability - In split-half reliability we randomly divide all items that purport to measure the same construct into two sets. We administer the entire instrument to a sample of people and calculate the total score for each randomly divided half. the split-half reliability estimate, as shown in the figure, is simply the correlation between these two total scores.
- Internal consistency reliability - Used to assess the consistency of results across items within a test.
- Interrater reliability - Used to assess the degree to which different raters/observers give consistent estimates of the same phenomenon
Validity (accuracy) – ability of the test to measure what it was designed to measure
- Content validity – degree to which the content of a test is representative of the domain its supposed to cover – If I asked government questions on a Psych exam
- Criterion-related validity (predictive validity) – estimated by correlating subjects scores on a test with their scores on an independent criterion (another measure) of the trait assessed by the test. ACT scores have correlated with college acceptance, college graduation, or levels of employment after college. Or AP scores with success in college, despite score on the AP exam.
- Construct validity – the extent to which evidence shows that a test measures a particular hypothetical construct --> Does a Happiness Inventory REALLY measure Happiness?