Personnel and vocational testing has made a huge impact in public and private organizations by helping organizations choose the best employees for a particular job (personnel testing) and helping individuals choose occupations for which they are best suited (vocational testing). The history of personnel and vocational testing is one in which scientific advances were influenced by historical and technological developments. The first systematic efforts at personnel and vocational testing began during World War I when the US military needed techniques to sort through a large number of applicants in a short amount of time. Techniques of psychological testing had just begun to be developed at around the turn of the 20th century and those techniques were quickly applied to the US military effort. After the war, intelligence and personality tests were used by business organizations to help choose applicants most likely to succeed in their organizations. In addition, when the Great Depression occurred, vocational interest tests were used by government organizations to help the unemployed choose occupations that they might best succeed in. The development of personnel and vocational tests was greatly influenced by the developing techniques of psychometric theory as well as general statistical theory. From the 1930s onward, significant advances in reliability and validity theory provided a framework for test developers to be able to develop tests and validate them. In addition, the civil rights movement within the United States, and particularly the Civil Rights Act of 1964, forced test developers to develop standards and procedures to justify test usage. This legislation and subsequent court cases ensured that psychologists would need to be involved deeply in personnel testing. Finally, testing in the 1990s onward was greatly influenced by technological advances. Computerization helped standardize administration and scoring of tests as well as opening up the possibility for multimedia item formats. The introduction of the internet and web-based testing also provided additional challenges and opportunities.