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232 Selected Studies on Software and Information Systems
need to have a static snapshot available as it is with WebVip. WET is based on principle of processing
of events generated by web browser. The disadvantage of such an approach could be
an overhead of records because what we would define as one user interaction could fire a vast
amount of events. E.g., a simple click on a hyperlink could result in a sequence of mouseover,
mousedown, mouseup a click. To address this issue, WET allows for setting explicitly which
types of actions are to be logged. That means that we can trace only clicks, page loads etc.
The problem of WET is its tight connection to the domain of web sites usability evaluation.
In fact, it creates an additional layer above the displayed page, providing control buttons to
manage the monitoring process. The Click tool (Client side action recorder) is inspired by
the logging part of WET (simple reference in a header part, optional types of events etc.) and
sends acquired data asynchronously using SOAP messages to the server side, to a specialized
web service.
UAR tool (User Action Recorder) is a standalone desktop application for Microsoft Windows
environment. It allows for monitoring not only user’s work within a web application
but whole user – computer interaction by tracking keyboard and mouse usage in individual
windows. These practically unlimited monitoring possibilities represents a significant disadvantage
of this standalone desktop application approach as many users would feel this as
a privacy threat.
8.5.3 Bootstrapping the User Model by Exploting Communities
We, people, are naturally integrated into several social communities (our relatives, friends,
colleagues etc.) and are strongly influenced by these communities. If one needs to solve
a “never-seen before” kind of a problem, she will very likely ask her friends for some hints
and help. We rely on other people if we are in some new and unknown situation, where we
are not sure about the most suitable action (e.g., “I will take the same food as others on the
conference dinner”). We are behaving socially.
The idea and advantages of social aspects in the real life is being transformed to the
web and its applications, namely to the Web 2.0. In fact, the models of social networks are
suppressing and replacing the traditional role of user model in web-based systems [3]. It is
becoming the community which has ever evolving characteristics and a helpful adaptation
can be provided on their basis (the system is performing community-based personalization
instead of user-model-based one).
The idea is taking advantage of the fact, that users are humans and humans tend to have
a lot in common. Use of social relationships in computer systems is not new. We know
collaborative filtering and history-enriched environments [30] as the results of pioneering
work from the early 90’s [27].
In fact, the cold-start problem got its name in the field of recommender systems based on
collaborative (social) filtering. User is rating the content and system is using these ratings to
compute user’s similarity to other users of the system. Then the system is able to recommend
new content which got high ratings from similar users. A recommender system can produce
good recommendations only after it has accumulated a large set of ratings, which is obviously
not the case for the new user, hence the cold-start problem arises.
The solution is to combine pure collaborative filtering with a content-based filtering
techniques, which selects items based on the correlation between the content of the items
and the user’s preferences [62] and to bootstrap the user model by other means.