Final answer:
The NCOER's primary function is to evaluate a noncommissioned officer's performance and potential for guiding Army personnel decisions on promotions, assignments, and career development.
Step-by-step explanation:
The primary function of the Noncommissioned Officer Evaluation Report (NCOER) is to provide a comprehensive and reliable assessment of a noncommissioned officer's (NCO's) performance and potential in the United States Army. The NCOER serves as a critical tool in the Army's personnel management system by guiding promotion, assignment, and career development decisions. It is intended to provide an accurate account of an NCO's abilities, accomplishments, and areas for improvement, establishing a record of their performance over a given evaluation period.