A Diary Study of Rendezvousing: Group Size, Time Pressure and Connectivity
Lecture Notes in Computer Science
This paper reports an initial analysis of a diary study of rendezvousing as performed by university students. The study's tentative findings are: (i) usability ratings for communication services are a little worse during a rendezvous (when at least one person is en route) than before (when none have yet departed); (ii) problems rendezvousing caused more stress when the rendezvousing group was large (6 or more participants) than when the group was small, but led to no more lost opportunity.
... ng (i) is attributed to the desire for instant communication (which is stronger when users are under time pressure), and the constraints placed upon interaction (which are tighter in public spaces than in personal spaces). Finding (ii) is attributed to the suggestion that large rendezvous include more acquaintances (whose contact details may not be known) and different kinds of subsequent activity. If rendezvousers need anything, this study suggests that they need greater connectivity and service availability, rather than greater bandwidth. Implications for the design of position-aware communications services are discussed. Aims This paper characterises some performance deficits associated with rendezvousingthe informal, geographical co-ordination of small groups of friends, family and team mates, such as "meeting a friend for lunch", and "collecting the kids from school". Rendezvousing is of general interest, because it is relevant to a wide range of possible services, such as personal organisation, navigation, information seeking, and communication. It is particularly relevant to position-aware services, because rendezvousing inherently involves a group of users moving towards a specific point in space and time, so position information seems particularly relevant. This paper is an initial analysis of the interim results of a large diary study involving UK university students. Phase 1 of this study was conducted in Spring 2001. Ten diaries were selected for analysis here. Phases 2 and 3 are currently being conducted (Spring 2002). The aim of this initial analysis is to make an early contribution to the development of position-aware communication services. Some such services, and toolkits for their development, are already available (www.benefon.com, www.gate5.de, www.ericsson.com/mobilityworld). This paper follows on from a previous diary study of rendezvousing, conducted in Spring 2000  . This pilot study (also based upon students) suggested that, if users did require an additional service to help them rendezvous, then a communication service was likely to be more frequently useful than, say, navigation or information services. The study found that approximately 5-10% of rendezvous caused a notable amount of stress and/or lost opportunity (rated at 4 or 5 out of 5, 5 = high). Given an average of 6 rendezvous per week, this proportion translates into a rate of about 1 'major problem' rendezvousing every 3 weeks -not obviously unacceptable, but also not obviously the best that could be achieved. The following reasons for rendezvousing problems were cited at least 10% of the time -transport delays, over-runs of previous activities, lack of information about other rendezvousers, lack of geographical information, promptness not being valued, and the spontaneous performance of additional tasks. The fact that rendezvousers very often had close personal relationships, and had met at that rendezvous point before, suggested that better communication was likely to be the most frequently useful at ameliorating the problem with such a range of causes. The previous study focussed upon the quality of outcomes, rather than 'costs incurred by users', because, with the benefit of hindsight, the conceptualisation and measurement of 'costs' was not the most appropriate. This paper complements previous work by focussing upon costs incurred by users, which are here measured in terms of usability ratings -satisfaction, effort, convenience, disruption, frustration, and social acceptability of communication services utilised. This paper also pursues the direction suggested by the previous study (position-aware communication), by attempting to identify the kind of rendezvous for which current communication services perform deficiently, and to suggest the kind of future communication service that has the potential to perform better. This paper, then, together with a previous one, prepare the ground for reporting of the full study.