What written exams really measure depends on the type of exam. A multiple choice situational exam basically measures a candidate's judgment, while a multiple choice textbook/regulations manual mainly measures book learning ability and study initiative. Other types of written exams, such as in basket and writing tests, measure important performance dimensions, but do not always assess oral communications and leadership abilities. It is essential that validity be built into written exams by insuring that both questions and answers are situational and relevant to the jobs for which candidates are competing. To double check exam validity, scores can be correlated against confidential supervisor and peer ratings of candidates' promotability. Rater bias can be minimized by using raters beyond the immediate supervisor level or by using forced choice evaluations in which phrases developed to describe important dimensions of promotability are given relative weights. Some police agencies have inhouse specialists available to develop and conduct promotional exams. Other options include having a consultant develop the exam or purchasing an off-the-shelf exam. Insuring that the exam is job-related and valid will help prevent legal challenges. 1 reference.