Summary - Psychological Testing and Assessment - Van der Molen - Chapter 5 & 7
Which theories about individual intelligence and performance tests are there? - Chapter 5
Topic 5A Theories of intelligence and factor analysis
Definitions of intelligence
Intelligence is one of the most researched topics in psychology.
Operational definitions define a concept in terms of the way the test is used. This way of defining is not useful for intelligence. Intelligence tests have been developed for measuring intelligence and not for defining it. In addition, operational definitions block the further development of the understanding of the nature of intelligence. A second problem is that the operational definition does not allow innovation. The old tests serve as a validity criterion for new tests. There must be a correlation between the old and new tests and in newly developed, innovative tests this correlation may weaken. According to the operational definition, they may therefore not be valid.
The real definition explains the true nature of the concept. To arrive at a true definition of intelligence, you have to ask experts. Several experts have come up with a definition. This list of definitions is Western and does not speak of cultural differences. The East thinks that benevolence, humility, freedom from conventional standards in assessment and doing what is right are essential for intelligence. In Africa, the social aspects of intelligence are emphasized. Despite all the differences, there are usually two things that everyone agrees on: intelligence is the capacity to learn from experiences and the capacity to adapt to the environment.
Another approach to understanding a construct is to study the popular meaning. Sternberg and colleagues did this and found out that the behaviors that are thought to belong to intelligence are quite similar to what experts think. The difference lies more in the order of importance.
When laymen think of intelligence, the following aspects are mentioned: practical problem-solving skills, verbal skills, and social competence. Experts mention the following aspects: verbal intelligence, problem-solving skills, and practical intelligence. This shows that public opinion on intelligence can be recognized in the intelligence tests.
The two parts that lay people and experts agree on are also not included in the tests. Firstly, because it is difficult to find items for these and secondly, because there has been little change in the design of the tests since the Binet time. Sternberg and colleagues have presented innovations that are based on their model of intelligence. Another interesting tool is the Everyday Problem Solving Inventory. In this test, participants should indicate how their response would be to everyday problems, such as forgetting your money when you go for lunch with a friend.
Factor analysis
Factor analysis is used to measure the validity of tests. There is confirmatory factor analysis and exploratory factor analysis. The first one checks whether test scores and variables fit in a predicted pattern and is therefore good for validation research. In the second, the relationships between many variables are summarized and it is examined whether they can be reduced to a lesser number of factors. It ensures that a simplified representation is given of a large, complex data set. Each collection of aptitude tests reflects a number of underlying basic skills.
A factor analysis starts with a correlation matrix, a table that shows correlations between different variables. Variables that have a high correlation with each other seem to explain a factor.
The smallest number of factors are determined by means of fast computers. Then a factor matrix can be made, which shows how heavily a variable weighs on a certain factor (values from -1.00 to +1.00).
The factor loads are then 'rotated', the best fitting variable is stopped at the best matching factors. In 'rotation to positive manifold', as many negative factor loads as possible are removed per factor. In 'rotation to simple structure', factor loadings are classified in such a way that each variable has a significant load with as few factors as possible. The aim is to make the factor matrix as clear and analysable as possible.
The interpretation of the factors that come out has to be done by the researcher himself. The researcher looks at what the variables of the factor have in common and then gives that interpretation. There are also disadvantages for factor analysis. Firstly, a certain factor can only come out of the analysis if the tests and measurements also contain that factor. Second, the sample size is important: around n=300 a factor analysis is stable and reliable. Finally, factor analysis is always subject to subjective choices and theoretical prejudices of the researcher.
Galton and sensory keenness
Galton thought that intelligence was explained by keen sensory abilities. The theory, however, had a dead end with regard to psychometry: it could hardly be tested. Later in the 1980s, however, reaction time tests were developed that measured the speed of processing. Even though these tests suggested that speed-of-processing measures could be a useful addition to standardized intelligence tests, these tests as well as their data analysis were not sufficiently standardized. That is why this method has not been developed much further.
Spearman and the g factor
Spearman stated that intelligence was based on a general intelligence factor g and several specific factors s1, s2, s3, etc. He focused primarily on defining the nature of g which he called the energy or power that generally appears in every context. The specific factor s represents a specific group of neurons that were used in certain mental actions. He found that individual differences in g reflected three principles of cognition: apprehension of experience, eduction of relations, and eduction of correlations. The word eduction can be rephrased as figuring things out. Even though Spearman’s speculations about physiology are for the most part dismissed, his notion of a general factor of intelligence remains relevant until today.
Thurstone and primary mental skills
Thurstone used factor analysis and concluded that not a single intelligence factor, but a group of factors, could explain empirical results. That brought him to his 7 primary mental skills: verbal comprehension, word fluency, number, space, associative memory, perceptual speed, inductive reasoning.
Later he argued that probably a general g factor was at the head and Spearman also stated that there are group factors that explain intelligence. Vernon felt that there was a hierarchy with the g factor at the top, then two group factors verbally and practically and then the 7 skills of Thurstone divided over the two factors.
Cattell-Horn-Carroll (CHC) theory
According to this theory, intelligence consists of three hierarchical strata. Stratum III is the general intelligence factor g. Stratum II consists of 8 parts, each with a number of specific skills of stratum I which are in brackets:
- fluent intelligence (5 specific skills): requires high thinking and reasoning and is used for new tasks that are not done automatically.
- crystallized intelligence (10): the breadth and depth of the knowledge of the individual.
- domain-specific knowledge (7): knowledge about specific domains that are not typical of culture.
- visual-spatial abilities (11): presenting, retaining and transforming mental representations of images.
- auditory processing (13): the accurate observation of auditory information and with it the capacity to analyze, understand and imitate patterns or groups of sounds.
- memory (13): the ability to consolidate new information and store it in the long-term memory and recall it later through associations.
- cognitive processing speed (7): the speed of performing automatic processes, especially when a lot of attention and concentration is needed.
- reaction time (5): the ability to make quick decisions in response to simple stimuli.
The skills of stratum I are always expanded and renewed with research. In addition, this model is widely used because the broad and specific skills are empirically verifiable and they include meaningful and implications for the real world. Many psychometricians consider it having the strongest empirical foundation of any theory of intelligence. Others have proposed a larger list that also includes psychomotor, olfactory, and kinesthetic abilities.
Guilford and structure-of-intellect model
Guilford classified intellectual skills in dimensions of operations, contents and products. Operations are the type of mental actions that the test must contain. Contents refers to the nature of the materials or information that is offered. Products includes the different types of mental structures that the brain has to produce in order to arrive at a correct answer. He then had 5 x 5 x 6 = 150 factors of intelligence respectively.
It is a complicated model, but he has raised the suggestion that divergent production, the creation of several good possibilities for a single stimulus (as opposed to only constructing one correct answer to a stimulus situation), can also be part of intelligence.
Planning, attention and simultaneous and successive theory (PASS)
Luria adopted the theory ‘plans, attention, simultaneity and succession', a general theory about cognitive processing. His approach focuses on the mechanisms that process information and is therefore also called the information processing theory. According to him, analysis provides strong evidence for distinguishing between two basic forms of integrative activity of the cerebral cortex, allowing different aspects of the outside world to be reflected. The theory contains three functional units in the brain, whereby the processing of information takes place from the lower units to the higher units:
- The first part includes subcortical areas like the brainstem, midbrain, and thalamus. It allows us to regulate attentive processes and selective attention and to resist distractions.
- The second part contains the sensory parts of the cerebral cortex (parietal, temporal, and occipital lobes). Their functions are more lateralized and include simultaneous and successive processing.
- The third part is in the frontal lobes and is responsible for planning and engine output.
According to this theory, processing starts with attention and planning is the final step.
- Simultaneous processing (of information): this is characterized by performing different mental activities simultaneously. An example for which you need this is for example drawing a cube, you need spatial insight, motor skills etc.
- Sequential processing (of information): is necessary for mental activities where a correct sequence of activities is needed. This is necessary, for example, for remembering a series of numbers.
Finding tasks that can test these two ways of processing in their pure way is the challenge for applying this theory to intelligence.
Information processing theories of intelligence
These theories propose models on how people represent and process information mentally. It is useful to make the analogy of a computer. The architectural system (hardware) comprises the biological requirements for information processing, such as coding speed. It is quite impenetrable to change by the environment.
The executive system (software) is easily influenced by the environment and it includes components related to the environment that control the problem-solving capacity and leading functional components. An example is metacognition, thinking about thinking, which is important for learning and intelligence.
Gardner and the theory of multiple intelligences
Gardner drew up a number of criteria for an autonomous intelligence:
- Potential isolation due to brain damage
- The existence of exceptional individuals in an area
- Identifiable core operations
- Distinctive developmental history
- Evolutionary plausibility
- Support from experimental psychology
- Support from psychometric studies
- Susceptibility to symbol encoding
Gardner thus established seven natural intelligences:
- Linguistic
- Logical-mathematical
- Spatial
- Musical
- Bodily-kinesthetic
- Interpersonal
- Intrapersonal
Bodily-kinesthetic intelligence includes the skills used by athletes, dancers, mime artists, etc. Personal intelligences include the ability to access both one's own feelings (intrapersonal) and the ability to notice and distinguish someone else’s moods, temperament, motivation, and intentions (interpersonal). People with musical intelligence can easily learn to play an instrument and make their own compositions.
Savants provide an important insight into the existence of different kinds of intelligences. A savant is someone who is mentally inadequate, but has developed himself in a certain area, such as music or art. The theory is compelling because of its simplicity, but the empirical validity is difficult to investigate.
Sternberg and the triarchic theory of successful intelligence
Sternberg has developed a theory that is called triarchic, because it emphasizes three aspects of intelligence.
Componential / analytical intelligence
Internal mental mechanisms responsible for intelligent behavior.
- Metacomponents or executive processes: these control the activities of the other intelligence processes, such as planning.
- Performance components: the processes that are used to perform a task or solve problems, such as working memory or syllogistic reasoning.
- Knowledge acquisition components: processes that are used in learning, such as the use of certain vocabulary in the right context.
Experiential / creative intelligence
- Ability to deal with novelty
- Ability to automize information processes
Contextual / practical intelligence
- Adaptation to the 'real world' environment: if you possess the skills needed for the culture in which you live.
- Selection of an appropriate environment: the ability to leave the environment you are in and to select an environment that is better suited to your talents and needs.
- Shaping of the environment: the skill to form the existing environment in such a way that it is more consistent with your needs.
For the theory, Sternberg has made the STAT (Sternberg Triarchic Abilities Test), which also contains creative and practical questions.
Topic 5B Individual tests of intelligence and achievement
Intelligence testing is one of the major achievements of the field of psychology. The score of general intelligence is often not what researchers are interested in. If they intending to determine g, any test would do. Often, however, they are looking for specific intellectual functioning and therefore look at the results of subtests, so it is important that they use the test that best describes what they want to know. There are many intelligence tests and new ones are added every month. The following tests are likely to be used in 95% of the assessment cases.
Orientation
This chapter discusses the following intelligence tests:
- Wechsler Adult Intelligence Scale (WAIS-IV)
- Wechsler Intelligence Scale for Children (WISC-IV)
- Stanford-Binet: Fifth Edition (SB5)
- Detroit Tests of Learning Aptitude-4 (DTLA-4)
- Cognitive Assessment System-II (CAS-II)
- Kaufman Brief Intelligence Test-2 (KBIT-2)
Wechsler Scales of Intelligence
The first intelligence test by Wechsler, the Wechsler-Bellevue Intelligence Scale, was released in 1939. He made sure that the test did not have the shortcomings of already existing tests. The existing tests were not available for adults, were too focused on manipulative words, were too focused on speed rather than accuracy, and the notion of mental age was irrelevant.
He drew up the new formula for IQ:
IQ = obtained score / expected mean score for age
He did this, because according to him IQ remains almost constant (IQ constancy), but intellectual skills can change over time. In addition, Wechsler hoped to use the test for psychiatric diagnoses. For this he distinguished between verbal and performance intelligence.
- Verbal> Performance (V>P): gave results for organic brain diseases such as psychosis and emotional disorders.
- Performance> Verbal (P>V): showed slight mental retardation in adolescents and adults.
Research has shown that there are many exceptions to this diagnostic rule, but it nevertheless showed that distinguishing between verbal understanding and perceptual reasoning (as we now know it) is useful in many areas, such as studying brain-behavioral relationships.
The later Wechsler tests were particularly successful because of the reliable content and formula of the first test, which meant that examiners, among other things, needed little training to switch to a new version.
The latest versions of Wechsler tests all contain the following common features:
- Thirteen to fifteen subtests that are used to measure intra-individual strengths and weaknesses rather than one global score.
- Empirically based scores and IQ scales. First it was subdivided into verbal IQ and performal IQ, but the latest versions have index scores in four areas:
- Verbal comprehension
- Perceptual reasoning
- Working memory
- Processing speed
- A common metric for IQ and index score, being an average IQ of 100 with standard deviation of 15. On a subtest this would be an average of 10 with standard deviation of about 3.
- Some of the same subtests for different test versions.
Wechsler subtests: description and analysis
Here the different subtests of the WISC-IV (children) and WAIS-IV (adults) are discussed.
- Information: this test tests factual knowledge about people, places and general phenomena. Most of these information questions are known when someone has grown up in a Western culture. This subtest also measures learning and memory skills, because one has to retrieve knowledge from memory. The information test is the best measure for general skills and relies heavily on the factor Verbal
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