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

Benedikt Schmidt, Todor Stoitsev and Max Mühlhäuser
(see table 4). Notably, users tend to use a similar vocabulary that partly follows <strong>the</strong> desktop metaphor.
The frequency hints to a repetition <strong>of</strong> similar actions for different tasks. Inserting <strong>the</strong> vocabulary in <strong>the</strong>
core execution processes identified in <strong>the</strong> previous section presents tasks as combinations <strong>of</strong> work
actions and higher level actions.
Ano<strong>the</strong>r striking aspect is <strong>the</strong> complexity <strong>of</strong> action-verbs. Some users make use <strong>of</strong> action verbs <strong>of</strong> low
complexity and precisely describe <strong>the</strong> access <strong>of</strong> a file or <strong>the</strong> typing <strong>of</strong> text. Whereas o<strong>the</strong>rs aggregate
whole sub-process through complex action-verbs, e.g. authoring involves file access and typing.
k 1
Task 2
k 3 Task 4
k 5
Task 6
k 7
Figure 3: Markov Chains for task execution processes (<strong>the</strong> darker a node, <strong>the</strong> more time was spend
using <strong>the</strong> node/<strong>the</strong> numbers at <strong>the</strong> edges denote <strong>the</strong> transition probabilities)
To get a better understanding <strong>of</strong> <strong>the</strong> meaning <strong>the</strong> different types <strong>of</strong> actions verbs, we have separated
<strong>the</strong>m. The action-verbs <strong>of</strong> low complexity are termed “desktop operations” and <strong>the</strong> complex
techniques are termed “knowledge actions” (<strong>the</strong> chosen terms follow work on regularities in work
execution, e.g. (Schultze, 2000), (Hädrich, 2008). A mapping <strong>of</strong> <strong>the</strong> user actions to desktop
operations and knowledge actions is visible in table 5. We consider <strong>the</strong>m as hierarchical connected,
i.e. an organizing knowledge action requires desktop operations like focus, cut etc. to be executed.
After a first extraction based on <strong>the</strong> user vocabulary <strong>the</strong> interaction histories have been used to
identify additional elements (five last elements in table 5). The resulting vocabulary <strong>of</strong> desktop
operations and knowledge actions allows <strong>the</strong> description <strong>of</strong> task execution processes. Core execution
processes can be created as combination <strong>of</strong> desktop operations and knowledge actions with
respective transition probabilities.
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