A 2003 meta-analysis by Arthur, Bennett, Edens, and Bell affirmed the effectiveness of organizational training by reviewing numerous studies. They identified four key types of measurement to evaluate training success: (1) the immediate reactions of employees to the training, (2) post-training assessments to confirm learning objectives were achieved, (3) supervisors' observations of on-the-job behavioral changes, and (4) tangible outcomes like increased productivity and profits. The analysis encompassed a wide range of training methods, such as self-instruction, lectures, and computer-based training.