Telling your own story: design and evaluation of a storytelling mechanic in a platform for serious games authoring.

End-User Development (EUD) researchers have been investigating methods and techniques so that, instead of computer experts, end users build applications themselves. However, these users have difficulties, for example, in understanding requirements, in making design decisions, in making use and reuse of components, and in carrying out integration and testing activities --- barriers to be overcome in the area. This paper presents the design, development and evaluation process of a storytelling-type game mechanic created to compose a platform for authoring digital games in which professionals can create their own games and use them with their populations of interest. The design was created together with professionals from different areas, in different stages, in order to consider a holistic view. The evaluation was carried out through usability tests that pointed out improvements to enable a more intuitive and easy-to-use interface. The storytelling game is an extra resource for health and education professionals, for example, to use as pedagogical or therapy tools.