Proceedings of the 12th European Conference on Knowledge ...

Benedikt Schmidt, Todor Stoitsev and Max Mühlhäuser
Word. A review <strong>of</strong> <strong>the</strong> complete interaction histories <strong>of</strong> user 14 and 15 shows that <strong>the</strong> preference is
not restricted to <strong>the</strong> single task, but is valid for all tasks.
The following sections need to elaborate on <strong>the</strong> role <strong>of</strong> different applications in <strong>the</strong> task execution
process. Notably, standard applications have a given purpose by <strong>the</strong>ir design (e.g. Mircos<strong>of</strong>t Word is
a text processor). Never<strong>the</strong>less, <strong>the</strong> role and <strong>the</strong> relevance <strong>of</strong> an application in a task execution
process are not completely prescribed by <strong>the</strong> design. The following sections investigate in <strong>the</strong> role
and <strong>the</strong> relevance <strong>of</strong> different applications for different tasks.
Table 3: List <strong>of</strong> used applications with accumulated focus time for all users
Application Name Focus time
Micros<strong>of</strong>t Internet Explorer 25 743
Micros<strong>of</strong>t Outlook 16 801
Windows XP - Explorer 9 238
Micros<strong>of</strong>t Word 7 214
Windows XP - Notepad 4 237
Acrobat Reader 4 216
Micros<strong>of</strong>t Communicator 4 024
Micros<strong>of</strong>t Excel 2 620
Mozilla Firefox 1 729
Micros<strong>of</strong>t PowerPoint 1 444
Windows XP - Calculator 350
Micros<strong>of</strong>t Visual Studio 50
Figure 1: Distribution <strong>of</strong> applications for task 5 executed by user 14 and 15
2.2.2 Application switches
Tasks are executed by a mixture <strong>of</strong> different applications. Switches between applications occur very
frequently during task execution. The data <strong>of</strong> <strong>the</strong> study includes 3229 application switches, resulting in
a mean usage duration <strong>of</strong> 25.8 seconds for an application before a switch occurs.
The amount <strong>of</strong> application switches differs with respect to <strong>the</strong> executed task (see Figure 2, left). Some
tasks, only have a low amount <strong>of</strong> application switches, e.g. task 2 (mean <strong>of</strong> 5.7 switches per task
execution). O<strong>the</strong>r tasks involve a high amount <strong>of</strong> application switches like task 5 (mean <strong>of</strong> 39.5
switches per task execution). Task 2 “Set up meeting” can be executed relatively straight-forward by
an experienced user, using only a few applications and resources. Task 5 “Paper from a foreign
language” involves multiple resources and requires <strong>the</strong> transformation <strong>of</strong> knowledge from one
resource to ano<strong>the</strong>r. For <strong>the</strong> given task an increase <strong>of</strong> information results in more application
switches.
Apart from <strong>the</strong> task, <strong>the</strong> switching behavior also has an individual characteristic. Figure 2 right shows
<strong>the</strong> amount <strong>of</strong> application switches per minute with respect to <strong>the</strong> user. Some users switch extensively
between applications and resource (e.g. user 18), while o<strong>the</strong>r users remain in one application for a
longer time and thus have a small amount <strong>of</strong> switches per minute (e.g. user 2). The video review
implied that <strong>the</strong> switch amount has no obvious reason but seems to be an individual characteristic <strong>of</strong>
work. Despite <strong>of</strong> <strong>the</strong> individuality <strong>of</strong> applications switches it is important to state that switches are
important facet <strong>of</strong> work execution. The following section will investigate which applications trigger
most task switches and which abstract processes emerge based on <strong>the</strong> switches.
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