Evaluate effectiveness of web design using information-search
tasks
As web pages become a mainstream mode of communication there is growing interest in evaluating their effectiveness. A common goal of web designers is to effectively represent information on a web site so that viewers can easily access information for which they are seeking. Eye-tracking technology provides a useful tool to help with this and other goals. Three straightforward examples of how the eye-tracker can be used in evaluating web pages is to look at
RT-to-target measure informs us of the effectiveness of the (low-level) features in capturing a person's attention. An effective feature could be one that is salient on a simple dimension (such as having a unique color) relative to surrounding information. This salient feature is likely to 'grab' our attention and thus 'pull' our eyes rapidly to this information.1) response time to reaching a targeted link (RT-to-target),
2) response time to select some information (RT-to-select)
3) accuracy in selection
Two demonstration studies Search for web information on. |
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Different goals in web search determine
what eye movement behaviors to study:
Determining which aspects of eye-movement (i.e., dependent variables) to
study depends on the goals of those creating the page ( presumably determined
by sponsoring organization) as well as those searching for information. When
focusing on marketing-- the organizational goal is effective advertising to
maximize product 'hits' and resulting sales . One such marketing concern in
education settings, involves student recruitment
and filling classrooms (virtual or otherwise), But presuming the mandate of
'education' as the priority. the goal now is optimizing student learning and
student success. What makes web design optimal for 'selling a product' vs.
'student learning' can be dramatically different. More superficial information
heaped with 'bells & whistles' can be very effective
in marketing. In this case, optimal web design would strive for the fastest
performance on RT-to-target and RT-to-select variables with little regard to
accuracy. But if the goal of optimal design is on
learning than semantic content becomes important and maximizing accuracy is
top priority, RT-to-target is lowest priority, As for the RT-to-select ,
what would be considered to be optimal for student learning may depend on educational
philosopy. Instructors interested in links that are easy-to-process and extract
their meaning may strive for rapid RT-to-select performance but those instructors
who believe that challenge and struggle are required for effective learning
may argue for slower RT-to-select performance. Perhaps the solution is to have
initial tests on experts who should achieve rapid RT-to-select performance
to demonstrate that the links do effectively convey intended meaning for those
with demonstrated expertise and understanding. In subsequent testing of these
same pages on student novices, RT-to-select may now serve as a measure of their
initial understanding and with repeated testing may serve as a measure
of their progress in learning.The research literature likely will offer useful
insights here but key message: goals matter when deciding which variables to
study.
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D.J. Aks
8/29/06
|D.J. Aks | Eye-tracking research | System noise | Time series & fractal analysis | Visual search | Attention | Satellite Imagery | Tumor detection | Web eval & info search | Illusions