Aligning work practices and mobile technologies Groupware design for loosely coupled mobile

Aligning Work Practices and Mobile Technologies: Groupware Design for Loosely-Coupled Mobile GroupsDavid Pinelle, Jeff Dyck, Carl GutwinHCI Lab, Department of Computer Science, University of Saskatchewan57 Campus Drive, Saskatoon, SK, S7N 5A9, Canada{david.pinelle, jeff.dyck, carl.gutwin}@usask.caask.caAbstract. Supporting mobile collaborative work over wide areas is challengingdue to the limitations and unreliability of wide area wireless networks. How-ever, variations in patterns of collaboration require different levels of timelinessand synchrony, and place different demands on groupware and its supportingtechnologies. In this paper, we argue that groupware supported by wide areamobile networks strongly favors loosely-coupled work, where workers areautonomous and require a reduced level of communication. We examine the re-lationship between loosely-coupled group characteristics and wide area mobilegroupware by considering one particular loosely coupled group—teams ofhome care workers. Over a two-year period, we analyzed home care work prac-tices, and designed and field tested MoHoC, a mobile groupware application tosupport home care work. From this experience, we identified four characteris-tics of loosely-coupled groups that enable workers to accommodate the uncer-tainty of wide area mobile groupware: autonomy and the partitioning of work,clear ownership of data and artifacts, asynchronous awareness, and explicitasynchronous communication.1 IntroductionIn spite of ongoing advances in mobile computing, when workers are mobile over a wide area, they must rely on uncertain networks that experience disconnections and variable throughput [25]. The difficulties seen in mobile networking are particularly constraining when we consider designing groupware technologies for widely dis-persed and mobile collaborators. Small group collaboration requires that members coordinate their activities, stay aware of others’ activities, and explicitly communicate with each other [15]. This level of interaction is particularly challenging to support using mobile technologies when synchrony and timeliness of information is an issue.In this paper, we will consider one particular type of mobile group—loosely-coupled mobile groups—where workers are not strictly dependent on synchrony and up-to-date information from other group members. Churchill and Wakeford [2] have suggested that the level of coupling between workers is a useful design dimension when building CSCW applications for mobile groups. We expand on this work by focusing on one particular type of coupling, loose coupling, and considering how thisstyle of collaboration shapes work patterns in mobile groups, and the implications these patterns have for groupware design. Pinelle and Gutwin [22] describe loosely-coupled mobility as work where group members are generally autonomous and rarely synchronous, and are often able to function without ongoing interaction with others, although they still are interested in staying aware of others’ activities. In this paper, we present results that suggest that these group characteristics are well suited to mo-bile groupware since they accommodate the uncertainties of wide area mobile technologies.We examined the relationship between the characteristics of loose coupling and wide area mobile technologies by studying one type of loosely-coupled mobile group—home care teams in Saskatoon District Health (SDH), a health district in Saskatchewan, Canada. In SDH, teams of community-based healthcare workers pro-vide patients with services in their homes, and they carry out their work in a loosely-coupled fashion. In SDH—unlike many other mobile settings (e.g. [10], [1], [21])—work is not arranged to facilitate regular synchrony. Workers do not have regular meetings, and do not see each other face-to-face very often. There is a high degree of variability in terms of schedule and location within a team and because of this, com-munication is difficult, and workers often carry out their work autonomously and without the benefit of regular input from others.Over a two-year period, we analyzed the work practices of home care teams, we designed and built a mobile groupware system to support these work practices, and we evaluated the system during a 2-½ month field trial. From this process, we identi-fied four characteristics of loosely-coupled work that allow workers to cope with many of the uncertainties of wide area mobile networks, and that make workers resil-ient to the difficulties these uncertainties introduce in mobile groupware design: •Workers are autonomous and partition work so that the need for ongoing coordi-nation and planning is minimized.•Artifacts and data are, in most cases, clearly owned by specific workers, so the need for negotiation and coordination of access is minimal.•Workers are rarely synchronous, so they rely on asynchronous means for gather-ing awareness information, which allows them to tolerate delays.•Workers carry out most of their explicit communication asynchronously, and are able to tolerate the delays inherent in these exchanges.For each work characteristic, we will discuss how it shaped the approaches we took in implementing MoHoC, a groupware application we developed for home care clinicians in SDH. We will discuss the results of a 2-½ month field trial we carried out with the application and the influence the introduction of MoHoC had on work practices. Finally, we will consider problems associated with our approaches, and the implications these have for groupware design.2 Related workMobile work practices shape the type of groupware support that is needed by mobile collaborators. For example, Kristoffersen et al. [14] propose using real-world scenar-ios to guide the design of mobile CSCW applications. However, as pointed out by Dix et al. [4] the interaction offered by mobile applications is also a product of the mobile device and the underlying infrastructure used to realize the application. In this section, we review related work on loosely-coupled mobile groups and on mobile computing technologies to illustrate how they shape mobile groupware designs.2.1 Loosely-coupled mobile groupsIn this paper, we investigate loose coupling as the primary means of organizing work and collaboration in a mobile group. Grinter et al. [12] describe loose coupling as work that occurs relatively independently of others, and that requires a reduced level of communication. Olson and Teasley [20] further elaborate on this idea: “loosely coupled work is work in which people need to be aware of others’ activity and deci-sions, but without the need for immediate clarification or negotiation. The work can proceed in parallel.” (p. 422). Loose coupling, then is a style of collaboration in which workers can function in a somewhat autonomous fashion without reliance on ongoing interaction with others. However, workers still need to stay aware of others’ activities in order to manage group interdependencies.In this research, we are interested specifically in loose coupling and mobility. Pinelle and Gutwin [22] characterize loose coupling in mobile groups by describing four work patterns that can occur. First, since workers are autonomous and communi-cation can be difficult, workers carefully consider the effort required to share infor-mation and select communication channels that minimize effort and overhead. Sec-ond, workers utilize awareness information from shared artifacts and locations as the lowest cost means of collecting information about others. Third, workers show a preference for asynchronous communication and coordination techniques since it allows them to deal with schedule and location variability. Forth, mobility and worker autonomy makes it difficult for workers to achieve synchrony, so synchronous col-laboration and back-and-forth discussions are limited, thus changing the nature of information that is shared. These findings show that managing work interdependen-cies is important in loosely-coupled mobile groups, but that the level of effort re-quired to stay aware of others and to explicitly communicate shapes work patterns, and has implications for design that must be dealt with by groupware developers.2.2 Mobile groupware technologyThe wireless networks used to support wide area mobile collaboration introduce many challenges and limitations, as discussed in Satyanarayanan [25] and Edwards [9]. Mobile networks are less reliable than wired networks due to two main factors: interference and signal strength. For mobile workers who work across a wide area, both interference and signal strength change frequently due to changes in location as well as natural variability.Variations in interference and signal strength have consequences on collaboration. Some of the direct effects are periodic disconnections, loss of data, and long delays due to congestion, retransmission, or low bandwidth. Several techniques have beenoffered that lessen some of these consequences under particular circumstances. Data replication (e.g. [23]) and caching increase availability of information during periods of disconnection and reduce delays. Consistency problems can be mitigated using optimistic replication schemes [24], automatically resolving conflicts when they hap-pen (e.g. [3]), and representing conflicts to the user (e.g. [24]). Adaptive strategies (e.g. [24], [19]) allow systems to make better use of their available resources, which can also lessen delay problems and help to make smooth transitions from connected and disconnected states [9]. Although these techniques have made many mobile col-laboration problems more manageable, evidence suggests that it is still difficult to mitigate, predict, and cope with wide area mobility problems at the user, application, and infrastructure levels [13].3 SettingWe have been working with clinicians and administrators in the Home Care de-partment at Saskatoon District Health (SDH), a health district in Saskatchewan, Can-ada, for the past two years as part of an ongoing project to develop group support technologies for home care workers. The functional unit for managing a community-based patient’s care in SDH is a treatment team—a group of workers who separately travel to a patient’s home and deliver a range of services to that patient. Treatment teams can be made of workers from several clinical disciplines, including occupa-tional therapists, physical therapists, social workers, nurses, case managers, and home health aides. Since each worker treats multiple patients during a workday (usually 6-15 depending on the discipline), and since teams are formed around patients, each worker is a member of multiple teams.Home care workers spend most of their time providing services to patients in their homes and driving between appointments. In addition to this, workers must spend time filling out forms that document their treatments and the interactions they have with patients. Workers have few technologies to assist them in these activities. SDH does not provide workers with mobile phones, but some workers use their personal phones while working. They have voicemail access, and nurses and home health aides carry one-way numeric pagers.Work practices in SDH can be characterized as loosely-coupled. Workers are autonomous, they are mobile and dispersed, and they communicate with each other intermittently. They autonomously set their schedules, determine their own work activities, and carry out work individually. Workers spend much of their time carry-ing out tasks that are not easily interrupted for communication, such as driving and delivering treatments in patients’ homes, and it is difficult for them to maintain an awareness of others’ locations, availabilities, and schedules. These work patterns can make collaboration difficult, and workers usually only communicate with each other intermittently, and often only when they believe the necessity of communication outweighs the effort required to communicate. When they do communicate, they usually rely on asynchronous channels such as voicemail, handwritten notes, and messages passed through office staff. In spite of the intermittent nature of collabora-tion, workers are still interested in others’ activities, and attempt to maintain anawareness of them. But the difficulty inherent in communicating and sharing informa-tion means that this awareness is often incomplete.4 MethodOur research activities initially focused on developing an understanding of workers, organizational structures, and work activities that are part of home care delivery in SDH. We began by carrying out three rounds of 1 to 1 ½ hour interviews, and during each round, we interviewed a member of each clinical home care discipline, for a total of seven interviews per round. In addition to the interviews, we spent approxi-mately 60 hours carrying out field observations to develop a detailed understanding of workers’ day-to-day work activities.We analyzed audiotapes and field notes and used the findings to guide the devel-opment of early prototypes of MoHoC, a groupware system to support home care teams. We carried out ongoing prototype reviews with home care clinicians to refine our designs. Once we felt that we had adequately validated our approach, we imple-mented the design as a mobile groupware system.We carried out a 2-½ month field trial of our system with a team of six home care workers from different disciplines. During the field trial, each worker carried a laptop and wireless CDPD modem. The treatment team used the application to support the treatment activities that they provided to a shared patient. Workers used the applica-tion to schedule visits, establish treatment plans, document treatments, and to explic-itly collaborate with each other. During the field trial, we carried out two rounds of interviews, and we met with each participant for 1 to 1 ½ hours per round. Upon completion of the field trial, we analyzed transcripts, system logs, and the private and shared workspaces that were utilized by workers during the trial.5 MoHoCWe developed MoHoC to accommodate the loosely-coupled work practices that are seen in home care in SDH. Our primary goals for the design were to support autonomous work, provide workers with information about the activities and deci-sions of other workers who treat shared patients (information that is currently often difficult for them to obtain), and provide workers with low-effort tools for explicit communication. MoHoC does this by giving workers private information spaces, and common information spaces that show artifacts that are created by other workers and UI representations that provide a range of information about other team members’ activities. MoHoC supports common home care activities such as scheduling visits with patients, clinical documentation, and treatment planning.MoHoC uses a robust client-server model with a centralized network architecture and replicated data views. During the field trial, we deployed the MoHoC client ap-plication on laptop computers connected to the Internet using the wireless CDPD network. The CDPD network in the field trial area is low bandwidth (19.2 kb/secmax; 11kb/sec max observed), and disconnections are both frequent and difficult to predict. The server was deployed on a reliable, dedicated machine with high capacity and a reliable cable network connection.The MoHoC server maintains a master copy of all data, with replicated data views stored locally on laptops for use by each worker. All messages sent between workers are sent through the server, which reduces the effects of disconnections by allowing messages to be sent between workers even though they might not be online at the same time. When a worker’s actions require a message to be sent, it cannot be as-sumed that a connection to the server will be available. To handle this, outgoing mes-sages are stored in a reliable message queue on the laptop’s hard drive and are not dequeued until they are confirmed as received by the server. This allows workers’ laptops to maintain outgoing messages if the system is turned off or in the event of a system crash, and the queue is FIFO (first in, first out), so it guarantees that transac-tions are transmitted to the server in the order that they are carried out. The server uses a similar queuing method to send messages to workers’ laptops.MoHoC uses connection and data replication transparency ([8], [27]). The workers are not aware of the status of their connection or of the status of other workers’ con-nections. They are also unaware of the messages in message queues and of how up-to-to the information is that is stored on their laptop. We decided to support transpar-ency since most home care workers have little previous experience with computers and with client/server architectures.6 ResultsThe results of our study show that four loosely-coupled group characteristics are particularly significant to mobile system design: autonomy and the partitioning of work, clear ownership of data and artifacts, asynchronous awareness, and explicit asynchronous communication. For each characteristic, we consider how it shaped the overall design of MoHoC and the impact of these approaches on work patterns during the field trial. We discuss the implications of our findings in section 7.6.1 Autonomy and the partitioning of workIn loosely-coupled work, workers are autonomous and partition work so that the need for ongoing coordination and planning is minimized. This implies that the division of work is mutually understood within the group so that workers do not need regular consultation with others. This autonomy can be seen in SDH, where workers serve in well-defined and mutually understood roles within groups, and are responsible for handling issues that fall within the scope of their expertise. For example, nurses han-dle wound care issues and physiotherapists handle ambulation issues. This allows workers to handle problems that they identify within the domain of their expertise without first checking with others.In loosely-coupled work, the autonomy of workers and their implicit understand-ing of work duties frees groupware developers from some of the constraints oftightly-coupled coordination (e.g. [28]). In mobile work, this is particularly important since workers may at times need to work in a disconnected fashion without access to the most recent information from other team members. This tolerance for loose coor-dination and autonomy allows groupware support to be feasible using mobile comput-ing techniques such as data replication and caching, where workers have a copy of relevant data on the mobile computing platform and can save their work locally when network access is unavailable until it can be forwarded to the server.In MoHoC, we used a data replication technique that provides mobile clients with a local copy of all relevant data. All SDH workers who treat a given patient receive all documents, appointments, treatment plans, and awareness-related data that are pertinent to that patient’s care. So, for example, if a worker adds an appointment with a given patient, that appointment is cached locally and then sent to the server as soon as a network connection is available. The server then forwards that appointment to all other workers who treat that patient as soon as a connection is available so that the appointment is viewable by all members of the treatment team.The field trial results indicate that this data replication and caching approach was overall very successful. Since SDH work patterns are autonomous, workers liked knowing that they did not need to be concerned with the state of the network—they could continue to work regardless of the state of the connection. Workers carried out their work activities knowing that the system would exchange information with the server whenever possible. They felt that having information about other workers was a benefit, and since they are accustomed to working without up-to-date information, they were not concerned with their information being out of synch.6.2 Clear ownership of data and artifactsIn loose coupling, the partitioning of work can extend beyond the specific duties and roles of group members to the artifacts used during work activities. For example, to carry out specific duties, workers may need certain data or shared artifacts. Since collaboration occurs in a loosely-coupled fashion, it is difficult to negotiate the coor-dination of access with others. As a means of accommodating this, workers may clearly own specific artifacts, so that the need for negotiation and coordination of access is minimal. For example, in SDH, each worker has clear ownership of his or her handwritten schedule and of the documents that they create about the care that they provide. They are the ones who are responsible for maintaining them, and are usually the only ones who are allowed to edit them.The loosening of coordination requirements that we see in loosely coupled mobil-ity has the potential to alleviate many of the complexities that are seen when imple-menting access controls in more tightly coupled groups (e.g. [16]). Since it is implic-itly clear to workers who is allowed to access or modify a resource, and since this is often an exclusive privilege, tightly-coupled strategies such as real-time updates of a shared workspace, and locking for editing are not necessarily required. Instead, more lightweight techniques, such as making it clear who owns what, and explicitly im-plementing permission policies can be sufficient to mediate access to work resources.In MoHoC, we handled these issues by allowing clear ownership of specific data items. Even though these items were visible to all team members, only specific work-ers were able to edit them. For example, a given worker is the only one who was able to establish their own appointments with a patient, and the only one who was able to edit the times for that appointment. However, that appointment is clearly visible in other workers’ workspaces.We had to handle added complexity when implementing policies for clinical docu-ments. In most cases, ownership and editing privileges of clinical documentation were clear. For example, a single nurse would treat a patient, and he or she was the only one allowed to create, edit, and delete the nursing documents. However, we also had to handle the case where two workers from a given discipline shared a patient. For example, during the field trial, two home health aides treated the same client—one during the day, and one during the evening. In this case, workers often had to edit documents that were created by a different worker of the same discipline. Our ap-proach to handling this was to allow workers of the same discipline who treat the same patient to append to existing documents. This mirrors real-world documentation practices, and it is able to accommodate network uncertainty. We time-stamped each transaction, and when new content was appended to a document, we sorted it into the appropriate chronological order in the new version of the document.During the field trial, these approaches were well received. As we might expect, data ownership fits existing autonomous work patterns, and this allowed workers to continue to work with the level of flexibility with which they are accustomed. How-ever, as we previously mentioned, two home health aides shared a patient across two different shifts. While this sharing took place in a loosely-coupled fashion, the in-creased interdependencies seen in document sharing between these workers caused some minor problems for these workers.We saw these problems in the home health aides’ use of flowsheets—checklist based forms that are used to record the services provided during visits. In most cases, several days worth of services are shown on a single flowsheet, and home health aides that share a patient also share the same flowsheet. However, during the field trial, this sharing did not always take place. By analyzing system logs, we found that on several occasions, one worker would create a new flowsheet, and that flowsheet would not reach the other home health aide who shared the patient in a timely fash-ion. The second home health aide, unaware of the existing flowsheet, would create a new flowsheet rather than adding to the already existing one, which led to an exces-sive number of documents being created and frustration for the home health aides. These problems arose due to intermittent network connections and workers not stay-ing online long enough to synchronize with the server and each other.6.3 Asynchronous awarenessIn loosely-coupled work, workers are rarely synchronous, so they rely on asynchro-nous means for gathering awareness information, which allows them to tolerate de-lays. Since workers have few direct interactions with each other, awareness informa-tion is not usually as readily available as it is in synchronous work situations. Instead,workers attempt to maintain an awareness of others not by observing them directly, but by collecting evidence of others’ past activities [22]. This means that delays are inherent in retrieving awareness information; however, workers are still able to func-tion with these limitations. For example, in SDH, workers gather information about others’ activities by looking for evidence of their activities in patients’ homes. This information is not available until they enter a patient’s home, and given that times between visits can be up to several weeks, long delays can occur.Unlike groupware that supports tightly-coupled groups by providing real-time and often transient awareness information (e.g. [7]), groupware for loosely-coupled col-laboration must account for the asynchrony of workers’ interactions. This asynchrony means awareness information must be persistent and available to workers whenever they access the system. As shown by Neuwirth et al. [18], when awareness is sup-ported asynchronously with groupware, workers should be able to view common work areas and easily develop an understanding of the state of shared work. This is particularly true since workers can be absent from the shared space for considerable time, and when they return they must be reminded of the work and how it has evolved since they last accessed the application. This concept of persistently available asyn-chronous awareness information is particularly valuable when designing groupware for widely distributed mobility since it is difficult to guarantee timeliness of updates, both because of work practices and technological constraints.In MoHoC we attempted to provide workers with a range of asynchronous aware-ness information that was intended to help them understand the actions of others so that they could make better decisions about patient care. This information was auto-matically collected from each worker while they carried out autonomous work activi-ties, passed to the server, and then routed to other treatment team members. When the information could not be pushed to a worker immediately, it was placed in a transac-tion queue on the server so that the sequential ordering of transactions would be pre-served, and then pushed out when a connection became available The information we shared in this way included viewing histories and modification histories of mutually accessible artifacts, schedule information, and information about treatment activities.During the field trial, workers regularly made use of awareness information. How-ever, there was an inadvertent side effect of the approach we took in our system. We found that since some workers might be away from work for a number of days due to holidays or illness, they would not log into the system during that period, and the cached awareness information that needed to be sent to those workers would pile up in the queue on the server. This was not a problem at the architecture level (i.e. the system was able to handle large queues), but when the worker logged into the system after being away for a number of days, it could take as long as 10 minutes for them to download the large number of enqueued awareness messages from the server. If the worker accessed the system for short periods of time during the day (e.g. 2-3 min-utes), it could take a prolonged period of time for the server side queue to empty, and for the worker to get the most recent updates. This was problematic since awareness information represented the clear majority of messages that were sent during the field trial.While the delays seen in asynchronous awareness may not necessarily seem to be a problem on the surface due to the loosely-coupled style of work, when a worker has。