TMRA TopiMaker – An Implementation of a Novel Topic Maps Visualization David De Weerdt Rani Pinchuk Richard Aked Juan-Jose de Orus Bernard Fontaine

TMRA Outline (1)What is TopiMaker? (2)Visualization requirements (3)2D in 3D world (4)Viewport, controls and camera movement (5)Ghosts as proxies (6)Exploiting the third dimension (7)Manipulating the Topic Map (8)Coping with information overload (9)Conclusion & future work

TMRA What is TopiMaker? ● Topic Map editor and viewer ● Developed by Space Applications Services ● Part of TopiWriter ● Alpha stage

TMRA Visualization requirements ● Variable level of detail ● Clustering of semantically close topics ● Highlighting of important parts ● Pleasant look ● Minimal change in the representation after Topic Map modification Representation requirements Navigation requirements ● Information should be accessible, explorable, searchable quickly and intuitively ● Information overload or hidden information should be avoided ● For both novice and knowledgeable users

TMRA Visualization requirements (2) F HB D E P NA G L R C K M Q I O J Original F HB D E P NA G L R C K M Q I O J Hide non-relevant parts F HB D E P N G L R C K M Q I O J F HB D E P N A G L R C K M Q I O J Highlight relevant parts B A F H DE P N A G L R C K M Q I O J Reorder B A F H DE P NAG L R C K M Q I O J Reorder and highlight

TMRA D plane in 3D world No 3D cloud: ● 3D cloud makes occlusion more likely ● Viewed from a distance, difference is small ● Degrees of freedom may obstruct construction of mental image ● Third dimension can be used for something else

TMRA D plane in 3D world (2) Placing the topics on the 2D plane, issues: ● Avoid overlapping topics ● Avoid crossing associations ● Maintain aesthetic properties such as symmetry and uniform distribution ● Speed ● Less relevant in TopiMaker though ● What happens when topics/associations are added or deleted?

TMRA D plane in 3D world (3) The placement algorithm: ● Based on force-directed placement method ● Topics (nodes) are placed on a grid ● No repulsive force between every pair of topics needs to be calculated ● Improvements: ● Non-random initial placement ● Variable goal association lengths ● Ending the algorithm with a few more iterations with smaller grid width

TMRA The viewport, its controls and camera movements Moving Rotating Zooming Automatic camera Selecting Duplicating views A B A B

TMRA Ghosts ● Surrogate topics ● Visually distinct ● Behave equally ● Optionally accompanied by table with neighbors

TMRA Exploiting the Third Dimension ● Bottom plane ● Top plane ● Middle plane ● Navigational aid

TMRA Manipulating the Topic Map ● Adding/deleting topics or associations does not change layout ● New topics are placed in the center ● Layout can be changed manually (dragging) ● Layout can be recalculated completely

TMRA Coping with information overload ● Do not draw superfluous data ● Tree-like associations can be drawn differently forearm Upper limb... thumb elbow... hand palm... part - whole forearm Upper limb... thumb elbow... hand palm... part - whole Upper body forearm Upper limb... thumb elbow... hand palm... part - whole Upper body Lower body chest... ● Clarifies hierarchical associations ● Lightens the main view ● Other possibilities ● Risk for overload

TMRA Coping with information overload (2)

TMRA Conclusion & future work ● Balance between representation quality and navigability ● Additional planes to highlight second (and third...) degree neighbors ● Zooming close → more topic info topic Occurrence1 Occurrence2 Occurrence3 Basename1 Basename2 Basename3 Parent1 Parent2 Parent3 Type1 SubjectID1 SubjectID2

TMRA Questions?

TMRA Thank you for your attention