Automatic Evaluation Methods of Trainee´s Answers to Develop a 4R Risk Prediction Training System

4 Rounds (4R) training method is practiced in industrial office site for reducing accidents caused by human factors. The 4R method enables to raise hazard-prediction capability of worker such as coping, decision-making to avoid danger situation. The workers as trainees train on their own by finding hazards which lurked in the hazard prediction training (KYT in Japanese) sheet. However, there is a large problem that a single trainee cannot train oneself using 4R method because the training of 4R method needs instruction of expert as human instructor. To solve that problem, we aim to develop hazard prediction training system. The advantage of this system enables trainee to train oneself anytime/anywhere using 4R method. In this research paper, we reports about our proposal of training system, the development of subsystem which based on machine learning to evaluate trainee´s answer correct or not, and reports the result of evaluation experimental that showed the average accuracy was 63.0±22.9 [%].