Effect or demand:the influence of effortful interaction on visiual perception

Recent developments in the field of human-computer interaction demonstrate that embodied interaction is becoming more common. This type of interaction tends to be seen as fun and natural but has one important downside, its reliance on bodily movement is effortful and can cause user fatigue (e.g. Cabral, Morimoto & Zuffo, 2005). While effort in interaction is known to exist, up until recently few researchers have considered the consequences of effort for the user beyond user comfort. Recently, however, such an influence was proposed. Van Beurden (2013) considered the effect of interaction gain for various input devices (e.g. mouse) and found that at low settings, and thus at larger bodily movements, distance reports for objects in mediated environments were higher for constant presentations. Based on the notion of Effort Theory it was argued that an effort mechanism may underlie these findings. This notion assumes that experienced effort may alter one’s visual perception (Proffitt, Bhalla, Gossweiler & Midgett, 1995; Bhalla & Proffitt, 1999). Currently, the scientific debate on this theory is highly topical and due to mixed empirical findings it is controversial. In light of the Effort Theory discussion, the suggested Effort Theory mechanism in human-computer interaction deserves further empirical clarification. The goal of the current research was to determine whether effortful human-computer interaction influenced visual perception and user experience. Based on a consideration of literature and pilot study results it was hypothesized that (1) effort effects of visual perception on human computer interaction would be found; (2) that inducing effort would deteriorate pragmatic user experience; and (3) that inducing weight would lead to an increase in hedonic user experience. Two experiments, based on Experiments 8 and 9 by van Beurden (2013), were conducted to investigate these hypotheses. In the first experiment participants estimated distances between two sequentially presented buttons on a computer display and effort was induced by manipulating mouse weight. After the experiment, experimental suspicion and user experience were assessed. Users were unaware of the experimental goals and no distance estimate differences between weight groups were found. In line with the hypotheses, however, there were indications that user experience may be dependent on effort. The second experiment consisted of a similar distance estimation task in a Virtual Environment. In this experiment, a stronger weight manipulation using a weighted 3D tracking device was applied. As with the first experiment, participants were found to be naïve about the experimental intentions and no effect of effort on distance perception was found. The user experience findings, however, surprisingly deviated from the hypotheses. Based on the findings from both experiments it can be concluded that Effort Theory does not reliably predict the results in either experiment. While these results could be seen as problematic for Effort Theory, an alternative explanation could be that the manipulation was too weak to cause an effect. Despite the fact that comparing exerted effort between conditions with van Beurden (2013) is difficult, the current work indicates that it is unlikely that earlier gain based findings can be explained in full by relying solely on an effort mechanism. The mixed user experience findings make it difficult to draw firm conclusions but have led to new and interesting questions about the interplay between experience of a device and the interaction user experience. Overall, the current work could be seen as one of the first to have investigated effortful interaction on visual perception and user experience. Future research could accommodate for identified limitations and demonstrate whether effort should be seen as an influential variable in human computer interaction.