An increasingly popular test format allows examinees to choose the items they will answer from among a larger set. When examinee choice is allowed fairness requires that the different test forms thus formed be equated for their possible differential difficulty. For this equating to be possible it is necessary to know how well examinees would have answered the items that they did not choose. In this paper, results are reported for an experiment in which 213 high school students who took the Advanced Placement Chemistry examination were asked to choose among several multiple choice items but were then required to answer all of them. It is concluded that allowing choice while having fair tests is only possible when it is unnecessary. (Contains 3 tables, 5 figures, and 14 references.) (Author/SLD)