The optimal allocation of Air Force talent requires, among other considerations, the measurement of both enlistee aptitudes and job aptitude requirements. Although objective procedures are available to measure aptitudes accurately, the procedure presently employed for establishing relative aptitude requirements is both unsystematic and subject to influence by extraneous factors. The Air Force Human Resources Laboratory has developed a systematic procedure for inferring relative aptitude requirements. It is based on occupational information collected at the task level. The measure issuing from this procedure is referred to as learning difficulty and represents the time it takes to learn to perform an occupation satisfactorily. The steps in the development of this procedure are (1) collecting supervisors' ratings of task difficulty, (2) obtaining benchmark task difficulty ratings from independent experts, and (3) analyzing these ratings for reliability and validity. Using this procedure, measures of occupational learning difficulty have been produced for more than 200 enlisted occupations or Air Force specialties. Use of these more refined measures of task assignment via aptitude measures may result in a more efficient use of Air Force personnel and ultimately cut down on attrition caused by job boredom. (Author/KC)