There are four procedures to present the implications of a correlation in terms of our ability to use the correlations to make successful predictions:Binomial effect size display (dichotomous)This illustrates the practical consequences of using correlations to make decisions. It can show how many successful and unsuccessful predictions can be made on the basis of a correlation. It uses the following formula:Binomial effect size display can be used to translate a validity correlation into an intuitive framework. However, it frames the situation in terms of an ‘equal proportions’ situation. Taylor-Russell tables (dichotomous)These tables inform selection decisions and provide a probability that a prediction will result in a successful performance on a criterion. The size of the validity coefficient (1), selection proportion (2) and the base rate (3) are required for the tables. Utility analysisThis frames validity in terms of a cost-benefit analysis of test use. Analysis of test sensitivity and test specificityA test is evaluated in terms of its ability to produce correct identifications of a categorical difference. This is useful for tests that are designed to detect a categorical difference.Validity correlations can be evaluated in the context of a particular area of research or application.A nomological network refers to the interconnections between a construct and other related construct. There are several methods to evaluate the degree to which measures show convergent and discriminate associations:Focusses associationsThis method focusses on a few highly relevant criterion variables. This can make use of validity generalization. Sets of correlationsThis method focusses on a broad range of criterion variables and computes the correlations between the test and many criterion variables. The degree to which the pattern of correlations ‘makes sense’ given the conceptual meaning of the construct is evaluated.Multitrait-...

Scaling refers to assigning numerical values to psychological attributes. Individuals in a group should be similar to each other in the regard of sharing a psychological feature. There are rules to follow in order to put people in categories:People in a category must be identical with respect to the feature that categorizes the group (e.g. hair colour).The groups must be mutually exclusiveThe groups must be exhaustive (e.g. everyone in the population can fall into a category).Each person should fall into one category and not more than one. If numerals are used to indicate order, then the numerals serve as labels indicating rank. If numerals have the property of quantity, then they convey information about the exact amounts of an attribute. Units of measurement are standardized quantities. The three levels of groups are identity (1), order (2) and quantity (3).There are two possible meanings of the number zero. It can be the absolute zero (1) (e.g. a reaction time of 0ms) or it can be an arbitrary quantity of an attribute (2). This is called the arbitrary zero. The arbitrary zero does not represent the absence of anything, rather, it is a point on a scale to measure that feature. A lot of psychological attributes use the arbitrary zero (e.g. social skill, self-esteem, intelligence).An unit of measurement might be arbitrary because unit size may be arbitrary (1), some units of measurement are not tied to any one type of object (2) (e.g. centimetres can measure anything with a spatial property) and some units of measurement can be used to measure different features of the same object (3) (e.g. weight and length).One assumption of counting is additivity. This requires that unit size does not change. This would mean that an increase of one point is equal at every point. This is not always the case, as an IQ test asks increasingly difficult questions to increase one point of IQ. Therefore, the unit size changes.Counting only qualifies as...

A utility analysis refers to a family of techniques that entail a cost-benefit analysis designed to yield information relevant to a decision about the usefulness and/or practical value of a tool of assessment. It is done in order to see whether the benefits of using a test outweigh the costs of that test. The objective of a utility analysis determines the required information (1) and the specific methods that have to be used (2). One method of utility analysis is expectancy data. This is converting the test data to an expectancy table. It can provide a likelihood that a test taker will score within some interval of scores on a criterion measure. Taylor-Russel tables provide an estimate of the extent to which inclusion of a particular test in the selection system will improve selection. It gives an increase in base rate of successful performance that is associated with a particular level of criterion-related validity. The selection ratio is a numerical value that reflects the relationship between the number of people to be hired and the number of people available to be hired. The base rate refers to the percentage of people hired under the existing system. Top-down selection is a process of awarding available positions to applicants whereby the highest scorer is awarded the first position. A downside of top-down selection is that this may lead to unintended discriminatory effects. HitA correct classification MissAn incorrect classificationHit rateThe proportion of people that an assessment tool accurately identifies as possessing or exhibiting a particular trait, ability, behaviour or attribute. Miss rateThe proportion of people that an assessment tool inaccurately describes as possessing or exhibiting a particular trait, ability, behaviour or attribute. False positiveA specific type of miss whereby an assessment tool falsely indicates that the test taker possesses a trait.False negativeA...