As the amount of information that must be understood by people continues to
grow, techniques for efficiently exploring large datasets become increasingly important.
Pan and zoom interaction has been shown to be effective for exploring
small datasets. However, pan and zoom on its own provides no visual cues about
regions of the dataset outside the current field of view, which can result in loss
of orientation, leading to inefficient patterns of navigation. Overviews offer one
possible solution to this problem by providing the user with contextual information
regarding regions outside the current field of view, at the cost of reducing
the screen real estate available for the primary detail view, and imposing the
need to switch attention between multiple views. Focus+Context techniques offer
another solution to this problem by integrating focus and context regions into
a single view, often using distortion-based methods, which themselves impose a
cost of tracking objects undergoing nonlinear transformations. While overviews
have been shown to be beneficial for pan and zoom interfaces, no study to date
has explored the potential benefits of adding an overview to Focus+Context
interfaces.
This thesis presents two studies that evaluate overviews for large tree navigation.
Interfaces implementing these techniques were used by 80 subjects, over
two studies, to perform a task exploring a large hierarchical tree dataset, which
was motivated by the needs of evolutionary biologists. Our first study was designed
to investigate the optimal size for an overview for both pan and zoom and
Focus+Context interfaces. Our results show that the size of the overview did
not affect performance, but the presence of an overview did impact the strategy
users adopted. Our second study was designed to compare the performance of pan and zoom and rubber sheet navigation techniques with and without an
overview. This thesis also presents the first step towards a taxonomy of tasks for
large tree navigation. Our taxonomy is informed from interviews with evolutionary
biologists who use large trees to investigate the evolutionary relationships
between species.
All interfaces implemented guaranteed visibility, a recent innovation in the
field of information visualization, which ensures that regions of interest remain
visible to the user at all times, independent of navigation actions. We discuss
the implications of this research, including the relationship between overviews
and guaranteed visibility, and propose directions for future work. / Science, Faculty of / Computer Science, Department of / Graduate
| Identifer | oai:union.ndltd.org:UBC/oai:circle.library.ubc.ca:2429/17735 |
| Date | 05 1900 |
| Creators | Bodnar, Adam Michael |
| Source Sets | University of British Columbia |
| Language | English |
| Detected Language | English |
| Type | Text, Thesis/Dissertation |
| Rights | For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use. |
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