Defining Uncertainties in Can You See Me Now?

Can you See Me Now? by Steve Benford, Andy Crabtree, Martin Flintham, Adam Drozd, Rob Anastasi and Mark Paxton is a journal paper to appear in ACM Transactions on Computer-Human Interaction, ACM Press. Nicolas considers it as a seminal article about ethnographical analysis of a location-based game. I see it at cornerstone of my current interest in the uncertainties inherent in pervasive environment. Projects like Can You See Me Now? are important not only to offer glimpses of potential new applications for location-based technologies, but they also provide a useful vehicle for HCI research, especially for studying how participants experience location and context sensing technologies and how they manage to coordinate distributed collaborative activities in spite of considerable technical uncertainties. Uncertainty is a complex issue that can affect users in different ways depending on their role, the extend of their technical knowledge, the context and the information available to them. Moreover, uncertainties are fundamental characteristics of location-based and mobile experiences, and they will remain so for the foreseeable future. While technology providers suggest that there are not limits to connectivity and mobility, service coverage and stability is anything but seamless in the real world.

I plan to have a look at theses issues from a different perspective by investigating other methodologies like mixing quantitative data from the system logs and qualitative data from post-game interviews to compare them with a performance index on the task. That is quantifying the impact of uncertainties on the task, while the work on Can You See Me Now? is to talk about the impact of uncertainties on the experience. I think there is a gap to fill between engineers delivering ubiquitous technologies and the practitioners envisioning services and solutions and the researchers analyzing the impacts (understand and explicit the combinations of social processes and technologies). That might explain the boring state of current Location-Based Services. Providing designer of pervasive games with cues like this paper does is good but not enough. It does not change an engineer’s perspective. Performance and impact indexes might do.

Overview
Benford et al. explicit the diverse ways in which players experienced uncertainties inherent in GPS and WiFi, including being mostly unaware of them, but sometimes seeing them as a problem, or treating them as a designed feature of the game, and even occasionally exploiting them within gameplay. They argue that designers should explicitly consider four potential states of being mobile participants – connected and tracked, connected but not tracked, tracked but not connected, and neither connected nor tracked. They then introduce five strategies that might be used to deal with uncertainty in these different states for different kinds of participants: remove it, hide it, manage it, reveal it and exploit it.

Sources of uncertainties
Sources of uncertainties in the game were GPS and WiFi. It proved to be a constant battle for a runner to get a GPS fix at all. Then analysis of system logs showed that reported GPS error ranged from 4m to 106m with a mean of 12.4m and a standard deviation of 5.8m. Even with a dense WiFi coverage. Both connectivity (packet losses) and latency were problems. Periods of short loss (less than 5 seconds) that account for 90.6% of loss intervals and were largely due to communication errors; 278 moderate periods of loss (between 5 seconds and 10min) that were largely due to detours out of the connectivity or interference; and finally two loss periods of about 15min and one of about 40, resulting from a major equipment failure. Although variable, there was a typical delay (latency) of six seconds or more between one participant acting and another participant seeing the actions. A final source of uncertainty was occasional technical failurs such as cables working loose and connectors being damaged as weel as “soft” failure such as batteries running out of charge.

The Mobile Player Four State of Being

• Connected and tracked
• Tracked but not connected
• Connected but not tracked
• Neither connected nor tracked

Designers need to consider how a player might end up in each of these states and should be done about it.

Five General Strategies for Dealing with Uncertainties

• Remove uncertainty: improving performance of existing technologies, mixing multiple sensing technologies or more pragmatically design the experience to closely fit the capabilities of the technology.
• Hide uncertainty: avoid setting unrealistic expectations through metaphors that cannot be delivered by the technology (i.e. avoid creating the illusion of a seamless world)
• Manage uncertainty: fall back to a downgraded but continuing experience. Uncertainty of connectivity might be dealt with by implementing baseline experiences for both street and online players that can continue when the connection between them is lost.
• Reveal uncertainty: Greater dialogue between users and ubiquitous technologies rather than designing for invisibility. The experience of Can You See Me Now? suggests that runners were better able to work with the uncertainties of GPS and wireless networking once they had build up a working knowledge of their presence and characteristics, provided by some information about estimated GPS error and connectivity on their mobile interface. This approach of revealing uncertainty is familiar from everyday mobile phones where information about signal strength is routinely made available to users to help them deal with uncertainty of connectivity. Experimental evidences state that revealing uncertainty can improve user performance. However this might lead to the trade-off between revealing and mental workload.
• Exploiting uncertainty: deliberately use uncertainty as a positive feature of an experience (creating engaging and provocative interfaces). Users can reflect more deeply if they are provided with a fuzzy representation that creates ambiguity.

Visualization that Reveal the seams
An ongoing work of Benford et al. is exploring how visualization revealing uncertainties can enable players to effectively interpret the ambituities encountered in gameplay. Their studies of gameplay show that players are already aware of seams in various ways.

Figure: Visualization of predicted GPS availability