as docking stations, chargers, headsets, cables, etc. In their work situations, and when moving between them, the workers switched the primary device they used quite often. There were even “frenzies” where this kind of juggling took place at intervals of less than five minutes. The workers actually perceived many benefits for having multiple devices instead of just one: more suitable display and manipulation mechanisms to choose from, reducing the time and effort needed to set up a device, being able to multitask, having devices as backup storages of data, improving personal “ergonomics,” choosing devices that are socially more acceptable, improving privacy, and securing company-sensitive data.

However, they were not able to achieve these feats easily— considerable effort, improvisation, and knowledge were needed. The main problems did not relate as much to the interconnection and operation of devices in situ, but to three things that we discuss below: 1) “being context-aware,” i.e., actively creating resources from what is available for using a computer; 2) “achieving seamlessness,” i.e., ensuring access to necessary data across situations and devices; and 3) “doing nondisruptiveness,” i.e., being able to gracefully align the use of computers with the physical,

Theo Humphries

Figure 1. Present-day ubicomp: the desk of a designer at the Royal College of Arts.

cognitive, and social demands of the situation at hand.

Being Context-Aware

Pre-trip planning is a nodal moment where beliefs about infrastructure become visible. There, a user must choose what devices to bring along and how to prepare them. The workers’ strategies of choosing devices ranged from conservative— always taking the same set of devices along—to opportunistic—taking devices “just in case”—to planned—planning the use of devices for each day or trip.

In the two strategies mentioned last, users exhibited being somewhat knowledgeable of which resources will be available and which not. The decision to take devices was accompanied by a variety of concerns— the battery life, wireless connectivity, or social acceptability in the future site of use.

Workers also exhibited per-
ceptual skills used to see oppor-

tunities in the surrounding environment to transform it for use. Figure 2 shows such “ con-text-awareness:” While waiting for a meeting to start, the worker made room for the use of his laptop by clearing the support surface of a beverage trolley.

The present-day ubicomp does not automatically adjust its provided resources according to users’ situations. Rather, it is the users who have to anticipate, search for, and plug into the computational resources, and for that they need knowledge of the upcoming situations and skill to adjust their own behavior accordingly.

Achieving Seamlessness

The notion of information access “anywhere, anytime” has been argued to be mainly a rhetorical notion [ 5]. Users are not really capable or even interested in having information available everywhere.

Trying to achieve “anytime, anywhere” when operating in

[ 5] Perry, M., O’Hara, K., Sellen, A., Brown, B., and Harper, R. Dealing with mobility: Understanding access anytime, anywhere. ACM Transactions on Computer-Human Interaction ( TOCHI) 8, 4 (2001), 323-347.