Assessment centers are not new. In 1991, the California Police Officers Association (CPOA) distributed a booklet entitled "The Art and Craft of Assessment Centers," which stated assessment centers were used by the German High Command in World War I to select officers with exceptional command or military abilities. During World War II, assessment centers were used by the Office of Strategic Services (OSS), a forerunner to the CIA, to select spies. Many private corporations used the assessment center format for promoting management personnel long before it was tried by public safety organizations.
In the late 1970s and early 1980s, law enforcement began to use assessment centers in selecting management personnel. During this time, Paul Whisenand, Ph.D., and George Tielsch, Ph.D., were two of many advocates of the assessment approach and wrote a book called The Assessment Center Approach of the Selection of Police Personnel, which explains in detail the assessment center approach and all of the dimensions it evaluates.
On a personal note, I am not a fan of assessment centers. I have been involved in numerous assessment centers both as a candidate and as a rater. But during my 17 years as chief, I only used the interview oral board process and was extremely pleased with the results. Assessment centers are overly expensive and if they are improperly facilitated and do not have trained raters, they are a waste of time. Many personnel managers and chiefs often try to develop an assessment center or mini-assessment centers on their own, but these processes are not validated and oftentimes do not produce the results intended. As CPOA states, "An assessment center simulates the job, it does not replicate it. Simulations, by virtue of being a simulation, create certain constraints, problems and artificial factors. If your chief or personnel manager states they will have an assessment center as part of their selection process then be sure to prepare properly for this process."
The best way to prepare for an assessment center is to change the way you think and prepare for promotion or selection into the job that is desired. CPOA believes that this is best done by determining what types of capabilities are necessary for successful performance on the job and then developing those capabilities. For example, basically all supervisory positions require oral communication skills. This particular attribute is measured in virtually every assessment center. Therefore, the individual must determine what degree in proficiency the job requires in oral communications. A similar must be undertaken for all the other skills that are a part of the job.
These assessment centers are designed to measure certain attributes or qualities of the candidate. These attributes or qualities are referred to as "dimensions." The following dimensions, as listed in the CPOA book, may change with each assessment center and how it is organized; therefore the following common dimensions should be used as guidelines only: