This study analyzes the work domain of position teaching in terms of means-end relations for the purpose of developing a practical support tool for human workers engaged in industrial robot teaching. A mechanical explanation model is introduced into the analysis to capture the force-displacement relationship inherent in and informative on the work system. The resulting models are used for the analysis of the robot operators’ decisions in search of accurate operation positions, and this in turn helps to clarify a rational operation strategy for making use of an invariant frame of reference in the position search space. After these findings, a prototype GUI is proposed that can provide effective information supports for different granularities of the activity in position teaching. Based on the principles of Ecological Interface Design, the proposed GUI represents the activity-related information in a way that encourages the robot operators’ intuitive and strategic operations.