  Usability is often defined as the ability of a system to carry out specific
tasks by specific users in a specific context. Usability evaluation involves
testing the system for its expected usability. Usability testing is performed
in natural environment (field) or artificial environment (laboratory). The
result of usability evaluation is affected by the environment in which it is
carried out. Previous studies have focused only on the physical environment
(lab and field) effect on the results but rarely focused on the effect of
social environment (people present during testing). Therefore, this study aims
to review how important it is to take context into account during usability
evaluation. Context is explored through the theory of behaviour settings,
according to which behaviour of individuals is strongly influenced by the
physical as well as the social environment in which they function. The result
of this review indicates that the physical and social context plays a
substantial role in usability evaluations. Further, it also suggests that the
usability evaluation model should encompass context as an important component
in the framework.
