Common design elements and strategies in participatory safety sign redesign among construction workers

This study investigated the mental models of construction workers on safety sign representations in participatory sign redesign. Twenty-three Hong Kong Chinese construction workers were asked to draw different safety sign referents and to narrate their drawings and redesign ideas. The drawings for each sign referent were assessed. It was revealed that the participants spontaneously divided the sign referents into components and portrayed the referents component by component. Four mental models on sign representation for referents were identified. The model of Complete and incomplete referents had a significant influence in participatory sign redesign, and the extent of agreement among workers on representation for incomplete referents was not easily reached. The model of Action words were expressed by portraying the results of an action or the situation that such kind of action would happen, and the graphical representations of the actions were concrete images of the tools used to realize the actions. The models of Prohibition and signal words were generally expressed through surround shapes but the choice of surround shapes seemed to be arbitrary. These results increased our understanding of the design rationale and justification and how the complete representation was built in sign redesign among construction workers. The findings help facilitate the process and practice of the user-involved participatory safety sign redesign in future.