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

Alexander Schneider and Alexander Steinh<strong>of</strong>f
change. When very long inputs are ignored (more than 30 characters – apparently copied into <strong>the</strong>
input field, not typed) <strong>the</strong> average number <strong>of</strong> characters changes from 9.34 to 8.10.
We expected that users would select entries higher up in <strong>the</strong> result list in <strong>the</strong> second phase because
popular pages now get a better rank. However, Figure 3 shows that users chose <strong>the</strong> first entry most <strong>of</strong>
<strong>the</strong> time already in <strong>the</strong> first phase. In <strong>the</strong> second phase <strong>the</strong> first entry is chosen even more frequently
but this is compensated by a worse performance for <strong>the</strong> cases when users select entries <strong>of</strong> <strong>the</strong>
second half <strong>of</strong> <strong>the</strong> list. Apparently users prefer to refine <strong>the</strong>ir query ra<strong>the</strong>r than scanning <strong>the</strong> complete
list <strong>of</strong> search results.
Figure 2: Percentage <strong>of</strong> uses <strong>of</strong> <strong>the</strong> search control where n characters (x-axis) or less were typed
before <strong>the</strong> users selected a search hit. The solid line represents <strong>the</strong> data collected in <strong>the</strong> first phase,
<strong>the</strong> dashed line that <strong>of</strong> <strong>the</strong> second phase.
Figure 3: Percentage <strong>of</strong> uses <strong>of</strong> <strong>the</strong> search control where <strong>the</strong> n-th entry (x-axis) or an earlier one was
selected. The solid line represents <strong>the</strong> data collected in <strong>the</strong> first phase; <strong>the</strong> dashed line that <strong>of</strong> <strong>the</strong>
second phase.
While it was not evaluated in detail, <strong>the</strong> usage data <strong>of</strong> <strong>the</strong> quick-search control suggests that <strong>the</strong>re are
valuable hints for <strong>the</strong> site administrators regarding <strong>the</strong> organization <strong>of</strong> contents. For some general
topics (e.g. "bachelor<strong>the</strong>sis") <strong>the</strong>re seem to be no appropriate links on <strong>the</strong> starting page – o<strong>the</strong>rwise
people would ra<strong>the</strong>r click <strong>the</strong>se links than type <strong>the</strong> search term. If even no appropriate document is
available via <strong>the</strong> quick-search, this indicates that a page for this topic should be created or a keyword
should be added to <strong>the</strong> right page respectively. This can be compared to <strong>the</strong> approach <strong>of</strong> (Happel
2009).
905