PYC4807_FINAL EXAM MEMO_ 1 2021.

PYC4807_FINAL EXAM MEMO_ 1 2021. Define the two types of criterion-related validity, describe the process of determining these and give an example of each. Briefly explain what it means if a test is biased in terms of criterion related validity. ANSWER: There are three types of validity or validation procedures, namely:  Content-description procedure,  construct-identification procedure and  criterion-prediction procedures. Criterion-prediction validity or criterion-related validity falls under the criterion-prediction procedures.  Criterion-related validity, a quantitative statistical procedure, can be defined as validity that involves the calculation of a correlation coefficient between a predictor or more than one predictor and a criterion.  Criterion-related validity can also be defined as the degree to which a measure is related to some standard or criterion that is known to indicate the construct accurately. There are two types of criterion-related validity that are distinguished by temporal positioning of the criterion measure in relation to the measure of the scale which is being validated: namely;  Concurrent validity: the degree to which a new measure is related to pre-existing measures of the construct. It involves the accuracy with which a measure can identify or diagnose the current behaviour or status regarding specific skills or characteristics of an individual. Implies the correlation of two (or more) concurrent sets of behaviour or constructs.  Predictive validity: refers to the accuracy with which a measure can predict the future behaviour or category status of an individual that are logically related to the construct. Implies that psychological measures can be used for decision-making. The distinction between these two types of criterion-related validity is based on the purpose for which the measure is used. To establish Criterion-related validity one has to compare the measure with another measure of the same construct, called criterion measure. 2 3 Test bias in terms of criterion-related validity is referred to as criterion contamination. This is the effect of any factor or variable on a criterion such that it is no longer a valid measure. The criterion must be free from any form of bias as this will influence the correlation coefficient with a predictor. Rating scales (e.g. performance ratings) are often used but they are subject to rating biases, where the rater may err on being too lenient or make judgements on a “general impression” of a person. The essential characteristics of predictive bias are that - it is a type of invalidity that prejudices one group more than another group;  group differences in test achievement are not reflected by corresponding differences in the behaviour domain that the test is meant to measure;  it involves constant and systematic errors (e.g. attenuation as a result of the unreliability of the criterion), in contrast to errors that can be ascribed to coincidental or chance factors (sample errors) in the estimation of the criterion score the constant or systematic errors are usually associated with group membership;  it leads to unfair discrimination against the group whose criterion score is under predicted, i.e. in practice the group does better in respect of the criterion than is predicted on the basis of the test scores. Bias in the predictive validity of a test can be investigated by making use of the o validity coefficient (i.e. the correlation between the test score and the criterion score), o slope and cut-off of the regression line and the standard error of estimate. Possible criterion measures include,  academic achievements,  performance in specialised training,  job performance,  psychiatric diagnoses,  rating and other valid tests. 3 ASJPR 4 Question 2 (a) Critically discuss the psychometric approach to intelligence and relate yourdiscussion to the South African context 4 5 ANSWER: The major focus of the psychometric or correlational approach to psychology is the study and measurement of individual differences in psychological characteristics, most notably, latent or inferred traits such as intelligence. The primary methods of statistical analysis – that is, correlational and, in particular, factor-analytic methods – are designed to discover the underlying sources of variation among individuals. Research is directed primarily toward determining or postulating the structure of mental abilities. Because the interest is on latent (unobservable) traits, the nature of such traits is inferred from theory and from research findings, such as the results of factor-analytic studies and validity studies. While these major psychometric theories are diverse in emphasis, each has contributed to the kinds of inferences we make about the nature of the latent variables of intelligence and thus to our understanding of what is measured by intelligence tests. Binet's emphasis on judgment and reasoning and, similarly, Spearman's principle of education of relations and correlates formed the foundation of most current conceptions of intelligence. Intelligence (g) is not what we know at a given time, but how well we can reason, solve problems, think abstractly, and manipulate information flexibly and efficiently, particularly when the stimulus materials present some degree of novelty. Novelty is common to g tests because the subject cannot fall back on already acquired knowledge or skill. The multiple factor theorists contributed the now-accepted concepts and measures of group factors of ability, for example, verbal, numerical, and spatial abilities. Thus they contributed the suggestion that intelligence is not a single unitary ability, but rather a composite of several or many components of ability, each of which may be important for different kinds of human endeavours. Vernon's hierarchical model is particularly useful in summarizing those aspects of intelligence related to academic performance. While present-day IQ tests measure g, they are often also heavily loaded with that cluster of abilities summarized by Vernon as v:ed, especially verbal abilities, and to a lesser extent numerical and spatial abilities. Because one of the major uses of intelligence tests has been to predict level of performance in schools, including colleges and universities, an emphasis on testing the verbal and symbolic (primarily numerical and spatial) abilities has developed. 5 6 Tests emphasizing Vernon's v:edare often referred to as “school ability” or “scholastic aptitude” tests. The important point about such tests is that although they are considered “intelligence” tests, they tend to assess those aspects of intelligence that are highly related to academic performance but may not assess other important aspects of ability. Catell’s concepts of “fluid” and “crystallized” intelligence have been useful in clarifying the differences between intelligence and achievement and in suggesting the addition of “learning ability” to our definition of intelligence. Essentially, Cattell's crystallized intelligence might be termed “achievement”, since it pertains to and measures acquired knowledge. Cattell's fluid intelligence is more similar in conception to Spearman's g– that is, the ability to see relationships in any content, familiar or novel. However, the causal analysis of the high correlations between gf and gc suggests that persons high in gf learn more readily and thus are more likely to score high on gcas well. An important aspect of intelligence, then, may be learning ability. To summarise these concepts: Intelligence may be considered a combination of 1. a general, or g, component reflecting overall reasoning and problem-solving abilities, judgment, and learning ability; and 2. subcomponents reflecting school ability and more specific group factors of ability representing various content areas or types of mental operations.The existence of g is inferred from the positive correlations among tests of mental ability varying in content and type of intellectual process involved, as long as those processes involve some form of mental manipulation rather than simple demonstration of acquired knowledge. The existence of separate components of gis inferred from factor-analytic studies.Different tests of intelligence differentially emphasize these components of mental ability, so an understanding of these components and their importance in different tests is important to the careful and effective use of tests of human mental ability. Discuss the purpose and rational of the Junior South African Individual scale (JSAIS) and indicate how the test relates to Spearman’s theory of intelligence. 6 7 ANSWER: Purpose: The first aim of the JSAIS is to measure as many of the intelligence related mental abilities as possible, but emphasizing those which are more closely associated with effective functioning at school, and therefore with the prediction of scholastic achievement.The aim is therefore to obtain a profile of the strong and weak aspects of a testee's intellectual functioning. The second aim is to measure the general factor of intelligence (Spearman's g factor). The third aim is to provide an instrument that can be used as an aid in diagnosing different levels of mental retardation in children with the further aim of providing them with different levels of special education. Rationale: With the construction of the JSAIS the assumption was made that intelligence may be regarded as consisting of related problem-solving abilities, some of which are more closely associated with effective functioning at school, and therefore, the prediction of scholastic achievement, than others. The further assumption was made that the total score on the tests included in the intelligence scale represents an underlying general factor of intelligence (Spearman's g factor) and that the socalled primary mental abilities are revealed at a lower level of generality and are related to different mental processes and different test content. The rationale for the selection of tests for the JSAIS was based on a process-x-content modelin which each of five processes is combined with three types of test material. The process and content facets are shown in Figure 1.