The model developed for this paper describes procedures for obtaining job relevant data for a needs assessment of principals' competencies to determine the discrepancy between their actual and desired performance. The major components of the model include selecting a committee to oversee the process, completing a job analysis, identifying and weighting required job competencies, measuring actual and desired performance, compiling and presenting needs assessment results, developing alternative procedures, validating professional development needs, and developing the program. A committee of five persons is selected from individuals with varying points of view regarding expectancies for the principalship, with expertise in competency identification. Job function identification yields a list of five to ten broad job functions. Based on these functions, a list of competencies or determinants of job performance is produced. The needs assessment survey is designed and implemented to provide supporting data and feedback on the identified competencies. A Quadrant Assessment Model is recommended to complete and present the results. The relationship between ideal competencies and the perceived relative priorities as expressed by practitioners is derived to establish job competency priorities. A comprehensive professional development program can result from this process. (JEH)