As we look at the history of assessment centers in nonmilitary settings since they were launched in the late 1940s in British civil service organizations and in the mid-1950s in the United States by AT&T, we see an interesting combination of continuity and change. Continuity is evident in the requirements that assessment centers include a number of essential common features. Change is evident in the many variations of these features. Changes have been instituted as a result of changes in the nature of work, organization structures, demographics of the workforce, and technological advances. In addition, variations are seen in assessment centers that are designed for different purposes. Variations in assessment center features are seen in:

the dimensions being assessed exercises used to simulate organizational situations the type of assessors used to observe and evaluate behavior methods to integrate data across exercises and assessors the type and level of detail in feedback provided to the participants,

managers in the organization, and HR staff

One of the reasons variation in these elements has appeared is the changing demographics of the workforce, including increasing involvement of minorities and women, persons with diverse ethnic backgrounds, and older workers. In addition, variations in assessment center practices have been

seen in cross-national applications. Throughout this book we explore many of these variations.