Visual Languages for Smart Spaces: End-User Programming between Data-Flow and Form-Filling

Visual end-user programming interfaces are becoming increasingly important in the context of smart homes. This paper describes the comparative evaluation of two prototypes following different approaches: form-filling and data-flow programming. We assessed rule completion time, success, user experience and rule recollection as well as suitability to different user-groups. Participants were significantly faster and had a higher overall completion rate using form-filling, but remembered significantly more items when being presented with a data-flow visualization. We therefore recommend approaches that imbibe characteristics of both approaches for end-user programming in a smart home context with untrained users, focusing on a guided process flow, explicit logic and content-categorization.