This paper describes the relative effects of task complexity on the retention of a skill over prolonged periods of non use. The paper focuses on the decay of skills and knowledges of the 20,000 reservists called up for active duty during Operation Desert Storm. Reservists were tested upon reentry to determine the extent of skill decay since their release, up to one year, from active. These data were analyzed with multiple regression and analysis of variance techniques. The major findings were: (a) procedural skills and knowledge about Army jobs decayed mostly within six months, but psychomotor skills (weapons qualifications) did not begin decay until ten months; and (b) previous skill qualification score was the best predictor of skill decay followed by aptitude score.
