Guidelines for avoiding legal problems: selection criteria based on job, adequate assessment of applicant ability, careful scrutiny of applicant-provided information, written authority for reference checking, save all records & information; reject applicants who make false statements. Selection ratio number of applicants hired / total number of applicants. Multiple-hurdle strategy approach to selection involving series of successive steps/hurdles; only candidates clearing hurdle are permitted to move onto next step; pre-screening, testing, interview, background check. Reliability interviews, tests, other selection procedures yield comparable data over time; degree of dependability, consistency/stability of measures used. Validity accuracy with which predictor measures what it is intended to measure. Differential validity confirmation that selection tool accurately predicts performance of all possible employee subgroups, including white males, women, visible minorities, persons with disabilities, Criterion-related validity extent to which selection tool predicts or significantly correlates with important elements of work behaviour.