What is Validity?
Validity is at the core of testing and assessment, as it legitimises the content of the tests, meaning the information gained from the test answers is relevant to the topic needed. For a test to be considered ‘valid’ it has to pass a series of measures; the first, concurrent validity, suggests that the test may stand up to previous analysis in the same subject, this is important as it relies on previously validated tests.
Criterion validity – a measure of how well what is being tested can predict future uses of the same kind; i.e. a personality test may predict a certain behaviour, but it is only valid if this behaviour is later shown in real life.
Predictive validity – similar to criterion in that it deals with the predictive nature of a question/task on a test; this type is often used when comparing tests scores on a work related task, to how an employee is actually scored on that task by their employer.
Content validity – mainly used in clinical psychology, measures an assessment on how well it encompasses the entire part of personality or symptoms it is testing for, and requires authorities to validate that these ‘parts’ make up the whole picture of what an illness, etc. is.
Construct validity – arguably one of the most important in psychometric testing, aims to review whether the test is actually testing what it’s meant to.
Why does it matter?
Validity is important in psychometric testing and the recruitment process, as it can give future employers a good idea of how applicants would get on in the position applied for. The various criteria fulfilled by the assessments, should hopefully insure that only the best, most well suited people are chosen for the job; not only this but if the tests were not valid it would be a waste of time and money for the company to use them.