In 1975 California became the first state to offer an "early exit" proficiency test from high school to persons 16 years of age or older (California law normally requires young persons to attend school until they reach 18 or graduate regularly from high school). More than 87,000 persons have passed the early exit examination; a pass rate of approximately 44 percent. The test was originally intended to serve the "bright but bored" students who may be performing well, but wish to move on to college early, and "borderline dropouts," marginal attenders and achievers who are disaffected with school but have gained or can gain a sound command of the basic skills before taking the test. This summary of the six years of implementation includes discussions of a longitudinal view of examinee characteristics, the long-term institutional reaction to the examination, changing test characteristics, and the relationship of the California High School Proficiency Examination to other testing programs. (CM)