This document describes the development and assessment of a methodology for generating on-the-job-training (OJT) task proficiency assessment instruments. The Task Evaluation Form (TEF) development procedures were derived to address previously identified deficiencies in the evaluation of OJT task proficiency. The TEF development procedures allow subject-matter experts (SMEs), without experience in assessment methodology, to construct task proficiency assessment instruments which can be used by OJT supervisors to assess trainee proficiency at specific tasks. The reliability and validity of the procedures and of the forms resulting from procedural application were examined in two Air Force career fields (Aircraft Maintenance and Security Police/Law Enforcement). The results of the procedural assessment indicated that SMEs could reliably apply the development procedures to construct TEFs which accurately and completely depict the critical aspects of task performance. The operational assessment demonstrated that evaluator subjectivity in the assignment of end scores and pass/fail decisions is minimized when TEFs are used. In addition, it was shown that evaluations conducted with TEFs provide end scores and pass/fail decisions which accurately reflect the number and types of errors detected in task performance. The combined results of the two assessments demonstrate the potential of the TEFs in the OJT environment. This document includes an overview of the theoretical approach and detailed descriptions of the assessment methodologies and results. The final section of this document contains recommendations for the integration of the TEF development procedures and the TEFs into the OJT environment. (Author)