Role of context in usability evaluations: A review <s> CONTEXT IN USABILITY EVALUATION <s> The article describes an active map service (AMS) that supports context-aware computing by providing clients with information about located-objects and how those objects change over time. The authors focus on the communication issues of disseminating information from an active map server to its clients, and in particular, address how to deal with various overload situations that can occur. Simple unicast callbacks to interested clients work well enough if only a few located-objects are moving at any given time and only a few clients wish to know about any given move. However, if many people are moving about in the same region and many clients are interested in their motion, then the AMS may experience overload due to the quadratic nature of the communications involved. This overload affects both the server as well as any slow communications links being used. Mobile distributed computing enables users to interact with many different mobile and stationary computers over the course of the day. Navigating a mobile environment can be aided by active maps that describe the location and characteristics of objects within some region as they change over time. > <s> BIB001 </s> Role of context in usability evaluations: A review <s> CONTEXT IN USABILITY EVALUATION <s> Current hardware developments are making mobile computing increasingly attractive. An important class of mobile applications are context-aware applications: applications that change their behaviour according to the user's present context-their location, who they are with, what the time of day is, and so on. This article is about software design for context-aware applications. Currently most such applications have been crafted by experts in research laboratories. Our aim is to factor out a simple class of context-aware applications and make the creation of these as easy as, say, creating Web pages. <s> BIB002 </s> Role of context in usability evaluations: A review <s> CONTEXT IN USABILITY EVALUATION <s> Situated computing concerns the ability of computing devices to detect, interpret and respond to aspects of the user's local environment. In this paper, we use our recent prototyping experience to identify a number of challenging issues that must be resolved in building wearable computers that support situated applications. The paper is organized into three areas: Sensing the local environment, interpreting sensor data, and realizing the value of situated applications. We conclude that while it is feasible to develop interesting prototypes, there remain many difficulties to overcome before robust systems may be widely deployed. <s> BIB003 </s> Role of context in usability evaluations: A review <s> CONTEXT IN USABILITY EVALUATION <s> Designing for usability involves establishing user requirements for a new system or product, developing design solutions, prototyping the system and the user interface, and testing it with representative users. However, before any usability design or evaluation activity can begin, it is necessary to understand the Context of Use for the product, i.e. the goals of the user community, and the main user, task and environmental characteristics of the situation in which it will be operated. This paper describes the background to, and importance of, understanding Context of Use, and presents a process for performing a context analysis. The method described is particularly aimed at non-experts in the area of user-centred design and evaluation. <s> BIB004 </s> Role of context in usability evaluations: A review <s> CONTEXT IN USABILITY EVALUATION <s> We describe an empirical, between-subjects study on the use of think-aloud protocols in usability testing of a federal data-dissemination Web site. This double-blind study used three different types of think-aloud protocols: a traditional protocol, a speech-communication protocol, and a coaching protocol. A silent condition served as the control. Eighty participants were recruited and randomly pre-assigned to one of four conditions. Accuracy and efficiency measures were collected, and participants rated their subjective satisfaction with the site. Results show that accuracy is significantly higher in the coaching condition than in the other conditions. The traditional protocol and the speech-communication protocol are not statistically different from each other with regard to accuracy. Participants in the coaching condition are more satisfied with the Web site than participants in the traditional or speech-communication condition. In addition, there are no significant differences with respect to efficiency (time-on-task). This paper concludes with recommendations for usability practitioners. <s> BIB005
Context is a term defined differently by different people. For example, Brown et al. BIB002 define context as location, identities of the people around the user, the time of the day, season, and temperature. Ryan et al  define context as the user's location, environment, identity and time. Hull et al BIB003 included the entire environment by defining context to be aspects of the current situation. Schilit et al BIB001 claim that the important aspects of the context are: where you are, who you are with, and what resources are nearby. Dey et al  define context to be the user's physical, social, emotional or informational state. Taking into consideration the various definitions of context, we found that one of the likely definitions of the context would be "context is anything which has an effect on the human behaviour". When evaluating the usability of any system, the behaviour of the user is very important. The factors which may affect the user behaviour needs to carefully considered because the result of usability evaluations may vary in different settings where the user may exhibit varying behaviours. Product usability doesn't take place in a vacuum; rather, it happens in context BIB005 . It is not meaningful to talk simply about the usability of a product, as usability is a function of the context in which the product is used. The characteristics of the context (the users, tasks, and environment) may be as important in determining usability as the characteristics of the product itself. Changing any relevant aspect of the context of use may change the usability of the product  . To understand the role of context in usability evaluation, it is necessary to examine what context is, and what aspects it comprise of. Many studies report that just physical location is the context. Context can be the cultural context  , organizational context, technological context or social context BIB004 . Since our focus is on the physical and social context, we explore each one of them in the next two sections.