This three-volume handbook is a comprehensive presentation of the theory and application of tests in psychology and education. It begins with an in-depth portrayal of psychometrics: the quantitative underpinning of testing. It then provides thorough, up-to-date and informative chapters related to five general application areas of testing: industrial/organizational psychology clinical psychology (including health psychology) counseling psychology school psychology educational testing In each of these five areas, this handbook is probably the most comprehensive review of the use of testing and assessment in the subfield.