Predictive validity
Encyclopedia
In psychometrics
, predictive validity is the extent to which a score
on a scale
or test predicts scores on some criterion measure.
For example, the validity
of a cognitive test for job performance is the correlation between test scores and, for example, supervisor performance ratings. Such a cognitive test would have predictive validity if the observed correlation were statistically significant.
Predictive validity shares similarities with concurrent validity
in that both are generally measured as correlations between a test and some criterion measure. In a study of concurrent validity the test is administered at the same time as the criterion is collected. This is a common method of developing validity evidence for employment tests: A test is administered to incumbent employees, then a rating of those employees' job performance
is obtained (often, as noted above, in the form of a supervisor rating). Note the possibility for restriction of range both in test scores and performance scores: The incumbent employees are likely to be a more homogeneous and higher performing group than the applicant pool at large.
In a study of predictive validity, the test scores are collected first; then at some later time the criterion measure is collected. Here the example is slightly different: Tests are administered, perhaps to job applicants, and then after those individuals work in the job for a year, their test scores are correlated with their first year job performance scores. Another relevant example is SAT
scores: These are validated by collecting the scores during the examinee's senior year and high school and then waiting a year (or more) to correlate the scores with their first year college grade point average. Thus predictive validity provides somewhat more useful data about test validity because it has greater fidelity to the real situation in which the test will be used. After all, most tests are administered to find out something about future behavior.
As with many aspects of social science, the magnitude of the correlation
s obtained from predictive validity studies is usually not high. A typical predictive validity for an employment test might obtain a correlation in the neighborhood of r=.35. Higher values are occasionally seen and lower values are very common. Nonetheless the utility
(that is the benefit obtained by making decisions using the test) provided by a test with a correlation of .35 can be quite substantial.
Psychometrics
Psychometrics is the field of study concerned with the theory and technique of psychological measurement, which includes the measurement of knowledge, abilities, attitudes, personality traits, and educational measurement...
, predictive validity is the extent to which a score
Test score
A test score is a piece of information, usually a number, that conveys the performance of an examinee on a test. One formal definition is that it is "a summary of the evidence contained in an examinee's responses to the items of a test that are related to the construct or constructs being...
on a scale
Scale (social sciences)
In the social sciences, scaling is the process of measuring or ordering entities with respect to quantitative attributes or traits. For example, a scaling technique might involve estimating individuals' levels of extraversion, or the perceived quality of products...
or test predicts scores on some criterion measure.
For example, the validity
Validity (statistics)
In science and statistics, validity has no single agreed definition but generally refers to the extent to which a concept, conclusion or measurement is well-founded and corresponds accurately to the real world. The word "valid" is derived from the Latin validus, meaning strong...
of a cognitive test for job performance is the correlation between test scores and, for example, supervisor performance ratings. Such a cognitive test would have predictive validity if the observed correlation were statistically significant.
Predictive validity shares similarities with concurrent validity
Concurrent validity
Concurrent validity is a parameter used in sociology, psychology, and other psychometric or behavioral sciences. Concurrent validity is demonstrated where a test correlates well with a measure that has previously been validated. The two measures may be for the same construct, or for different, but...
in that both are generally measured as correlations between a test and some criterion measure. In a study of concurrent validity the test is administered at the same time as the criterion is collected. This is a common method of developing validity evidence for employment tests: A test is administered to incumbent employees, then a rating of those employees' job performance
Job performance
Job performance is a commonly used, yet poorly defined concept in industrial and organizational psychology, the branch of psychology that deals with the workplace. It's also part of Human Resources Management. It most commonly refers to whether a person performs their job well...
is obtained (often, as noted above, in the form of a supervisor rating). Note the possibility for restriction of range both in test scores and performance scores: The incumbent employees are likely to be a more homogeneous and higher performing group than the applicant pool at large.
In a study of predictive validity, the test scores are collected first; then at some later time the criterion measure is collected. Here the example is slightly different: Tests are administered, perhaps to job applicants, and then after those individuals work in the job for a year, their test scores are correlated with their first year job performance scores. Another relevant example is SAT
SAT
The SAT Reasoning Test is a standardized test for college admissions in the United States. The SAT is owned, published, and developed by the College Board, a nonprofit organization in the United States. It was formerly developed, published, and scored by the Educational Testing Service which still...
scores: These are validated by collecting the scores during the examinee's senior year and high school and then waiting a year (or more) to correlate the scores with their first year college grade point average. Thus predictive validity provides somewhat more useful data about test validity because it has greater fidelity to the real situation in which the test will be used. After all, most tests are administered to find out something about future behavior.
As with many aspects of social science, the magnitude of the correlation
Correlation
In statistics, dependence refers to any statistical relationship between two random variables or two sets of data. Correlation refers to any of a broad class of statistical relationships involving dependence....
s obtained from predictive validity studies is usually not high. A typical predictive validity for an employment test might obtain a correlation in the neighborhood of r=.35. Higher values are occasionally seen and lower values are very common. Nonetheless the utility
Utility
In economics, utility is a measure of customer satisfaction, referring to the total satisfaction received by a consumer from consuming a good or service....
(that is the benefit obtained by making decisions using the test) provided by a test with a correlation of .35 can be quite substantial.