Some abilities needed for Federal jobs may be inherently more difficult to learn than others. Research on mental abilities distinguishes among those that can be developed through training, those that are unresponsive to training, and those that are moderately responsive. This dimension is known as "trainability." This report contrasts employee perceptions of the trainability of job-relevant abilities with research findings about the actual trainability of these abilities. The goal is to help agencies use training resources to enhance individual and organizational performance by highlighting abilities for which training may be less beneficial than other organizational improvement strategies. Charts and tables.