Standardization and Norms

Standardized

• Test items have been piloted on a similar population of people as those who are meant to take the test and that achievement norms have been established.

Standardization sample

• Used to establish reliable norms for the population that it represents.

Psychometrician

• People who make tests

• Use the performance of the standardization sample on the experimental sections to choose items for future tests

The purpose of tests is to distinguish between people

• Test questions that virtually everyone answers correctly as well as questions that almost no one can answer are discarded as they do not provide info that differentiate between people.

Reliability and Validity

Reliability

• Refers to the repeatability or consistency of the test as a means of measurement

Split-Half Reliability

• Randomly dividing a test into two different sections and then correlating people’s performances on the two halves

• The closer the correlation coefficient is to +1, the greater the split-half reliability of the test

Equivalent-Form Reliability

• The correlation between performance on the different forms of the test

Test-Retest Reliability

• Correlation between a person’s score on one administration of the test with the same person’s score on a subsequent administration of the test

Validity

• Measures what it is supposed to measure (accuracy)

A test cannot be valid if it is not reliable

Content Validity

• How well a measure reflects the entire range of material it is supposed to be testing

• Example: If you’re testing to find a good chef, a test that required someone to create a variety of dish types would have greater content validity

Face Validity

• Superficial measure of accuracy → extent to which the items or content of the test appear to be appropriate for measuring something, regardless of whether they actually are (type of content validity)

• Example: A test of cake-baking ability has high face validity if you’re looking for a chef but low face validity if you’re looking for a doctor.

Criterion-Related Validity

• Concurrent Validity

  • Measures how much of a characteristic a person has now

• Predictive Validity

  • Measure of future performance

Construct Validity

• The degree to which a test or instrument is capable of measuring a concept, trait, or other theoretical entity.

Types of Tests

Aptitude Tests

• Measure ability or potential

Achievement Tests

• Measure what one has learned or accomplished

Speed Tests

• Generally consist of a large number of questions asked in a short amount of time

• Goal is to see how quickly a person can solve problems

• Amount of time allotted should be insufficient to complete the problems

Power Test

• Gauge the difficulty level of problems an individual can solve

• Consists of items of increasing difficulty levels

• Sufficient time to work through as many problems as they can

Group Tests

• Large number of people at a time and interaction between the examiner and the people taking the test is minimal

Individual Tests

• 1-on-1 and involve a greater interaction between the examiner and examinee

Theories of Intelligence

Intelligence

• Typically defined as the ability to gather and use information in productive ways

Fluid Intelligence

• Refers to our ability to solve abstract problems and pick up new information and skills

Crystallized Intelligence

• Involves using knowledge accumulated over time

Charles Spearman

• Argued that intelligence could be expressed by a single factor

• Used factor analysis, a statistical technique that measures the correlations between different items

• Concluded that underlying the many different specific abilities s that people regard as types of intelligence is a single factor g (general)

Howard Gardner

• Subscribes to the idea of multiple intelligences

Daniel Goleman

• One of the main proponents of EQ (Emotional Intelligence)

Robert Sternberg

• 3 types of intelligence → componential or analytic intelligence, experiential or creative intelligence, contextual or practical intelligence

• Intelligent behaviour depends on the context or situation in which it occurs. Other theories of intelligence view intelligence as ability-based

Intelligence Tests

Alfred Binet

• Came up with the idea of mental age, an idea that presupposes that intelligence increases as one gets older

• Used mental age to identify how “intelligent” children were compared to their peers

Louis Terman

• Created the Stanford-Binet IQ test

• A person’s IQ score on this test is computed by dividing the person’s mental age by his or her chronological age and multiplying by 100

David Wechsler

• 3 different types: Wechsler Adult Intelligence Scale (WAIS) is used in testing adults, Wechsler Intelligence Scale for Children (WISC) is given to children between the ages of 6 and 16, Wechsler Preschool and Primary Scale of Intelligence (WPPSI) can be administered to children as young as 4.

• Used deviation IQ to yield IQ scores

  • The absolute measure of how far an individual differs from the mean on an individually administered IQ test (standard deviation is usually 15)

Nature vs Nurture: Intelligence

Heritability

• A measure of how much of a trait’s variation is explained by genetic factors

Nature or Nurture?

• Flynn Effect → the gradual cross-cultural rise in raw scores obtained on measures of general intelligence

  • Since the gene pool has remained relatively stable, this finding suggests that environmental factors such as nutrition, education, and perhaps, television and video games play a role in intelligence

• Monozygotic (identical) twins, who share 100 percent of their genetic material, score much more similarly on intelligence tests than do dizygotic (fraternal) twins, who have, on average, only 50% of their genes in common.

  • Nonetheless, some researchers have suggested that monozygotic twins tend to be treated more similarly than dizygotic twins, thus confounding the effects of nature with those of nurture

• Research on identical twins separated at birth has found strong correlations in intelligence scores

  • Researchers advocating more of an environmental influence point out that usually the twins are placed into similar environments, again making it difficult to sift out the relative effects of nature and nurture

• Psychologists agree that racial differences in IQ scores are explained by differences in the environment

• Participation in programs meant to redress some of the disadvantages faced by impoverished groups has shown to correlate with higher scores on intelligence tests.

  • Opponents of such programs assert that these gains are limited and of short duration. Advocates of such interventions respond that expecting the gains to outlast the programs is unreasonable.