How Do End-Users Program the Internet of Things?

Nowadays, end users can exploit end-user development platforms to personalize their Internet of Things ecosystems, typically through trigger-action rules. Unfortunately, within such platforms, users are forced to adopt a unique, vendor-centric abstraction: to define triggers and actions, they must specifically refer to every single device or online service needed to execute the intended behaviors. As a consequence, little social and practical benefits of end-user development in this domain have emerged so far. In this paper, we build on the idea that other abstractions besides the vendor-centric one are possible, and that the growth of end-user personalization in the Internet of Things may depend on their identification. Specifically, we report on the results of a 1-week-long diary study during which 24 participants were free to collect trigger-action rules arising during their daily activities. First, we demonstrate that users would adopt different abstractions by personalizing devices, information, and people-related behaviors, where the individual is at the center of the interaction. Then, we show that the adopted abstraction may depend on different factors, ranging from the user profile, e.g., their programming experience, to the context in which the personalization is introduced. While users are inclined to personalize physical objects in the home, for example, they often go "beyond devices" in the city, where they are more interested in the underlying information. Finally, we discuss the retrieved results by identifying new design opportunities to improve the relationship between users and the Internet of Things.