Seamful design: showing the accuracy of location predictions
Dearman, D., Varshavsky, A., de Lara, E., Truong, K.N. An Exploration of Location Error Estimation. To appear in the Proceedings of UBICOMP 2007: The 9th International Conference on Ubiquitous Computing (September 16-19, Innsbruck, Austria), 2007. The paper deals with location-aware computing and how location predictions often fails to report their accuracy. The authors propose to reveal the error of location prediction (in a very "seamful design" way) and evaluate different possibilities in a field study, showing significant benefit in revealing the error of location predictions.:
"Predicted Location. In the predicted location condition, we provided participant with the predicted location of herself and the poster
95% Confidence. In the 95% confidence condition, we provided participants with a region defined by a confidence ring, in which the application is 95% confident that the actual location is contained within the ring.
Customizable Confidence. In the customizable confidence condition, we provided participants (by default) with the same visualization as the 95% confidence condition; however, they could manipulate the confidence level of the ring.
Optimal Error. In the optimal error condition, we provided participants with a ring for each location (see Figure 3(e)) where the ring’s radius is defined by the true error of the location prediction."
What is very interesting here is the description of how users cope with the localization system and how they benefit from the presentation of the positioning error:
"Our results show that presenting an estimate of the positioning error provides a significant benefit. Fixed estimates of error (e.g., 95% confidence and customizable confidence) provided little additional benefit, but they do help confine the search area. The optimal error condition strongly and positively in- fluenced participants’ search strategies. Participants found all posters where the true error was small. When the true error was large, participants experienced the same problems for finding the posters as the participants in the other conditions. However, participants in the optimal condition could identify that the true error was large and differentiate between high and low true error, where as participants in all other conditions could not. "
Why do I blog this? because this field study is an interesting exemplification of seamful design, i.e. revealing the limits/shortcoming of a system to the users. Results are quite interesting as they express which sort of information can be valuable to the users.