Abstract
This paper describes an empirical study conducted to explore the expressive design space for what we dub "effortful interaction." Effortful interaction is a form of human-computer interaction where different degrees of physical effort are intentionally incorporated into the interaction design in order to communicate information. In this sense effortful interaction is similar to haptics, where devices provide physical force feedback to users, except the perceived feedback occurs entirely within users' proprioception: i.e., users' perception of their own bodies. Our larger design goal is to use effortful interaction to communicate quantitative information to children who aren't yet proficient with graphs. First, though, we had to establish if we could reliably induce sensations of effort. This study examined the sensitivity of children to three different design parameters (the duration of interaction, the intensity required by the interaction, and the physical modality of the interaction), and compares their responses to those of adults.