BIAS IN MEASUREMENT INSTRUMENTS. FAIR TESTS

Psychological assessment must ensure the equity and validity of interpretations and of any decisions taken as a result of them. That is it necessary the use of bias-free assessment instruments those are capable of evaluating the personal and social needs of individuals with different characteristics. The study about the possible bias of tests, or some of their items, has had great relevance in psychometric research for the last 30 years and it will probably continue to be an important focus of interest for professionals and researchers involved in psychological and educational testing. The aim of this paper is providing to the applied psychologist the background about bias, differential functioning and impact concepts, item or tests bias detection procedures and evaluation of its possible causes an d, therefore, for improving the validity of psychological measurement.