1. 1 Slicing*-Tree Based Web Page Transformation for Small Displays Xiangye Xiao, Qiong Luo, Dan Hong, Hongbo Fu Contact: xiaoxy@cs.ust.hk Department of Computer Science Hong Kong University of Science and Technology (HKUST)

2. 2 ●Problem  Web browsing on small displays  Small screen  Limited bandwidth and input devices ●Our solution  Divide a Web page into a multi-level hierarchy of smaller blocks with balanced fanout and height  Make each transformed page fit the screen  Use textually-enhanced thumbnails Overview

3. 3 Example: Transformed Pages (a) (b) (c) (d) (a)~(c): textually-enhanced thumbnails with multiple hyperlinks, displayed when corresponding sections are pen-tapped (d): a block from the original page Pen Tap

4. 4 Example: Textually-Enhanced Thumbnail Thumbnail of the part bordered with red lines The thumbnail is enhanced by the textual summary (keywords) of the corresponding part

5. 5 System Architecture Forwards the request and transforms the received Web page into a tree hierarchy of thumbnail index pages and leaf sub-pages. Returns the root index page to the PDA for display and stores the other sub-pages locally. Serves the user the corresponding sub-page that has been stored on the proxy, when the user selects a region in the index page.

6. 6 Page Transformation Process

7. 7 Example: Slicing*-Tree Representation The leaf blocks bordered with blue lines on the left correspond to the leaf nodes of the slicing*-tree on the right. The adjacent small blocks are merged according to their sizes, coherence of semantics, and layout. The merged larger blocks correspond to the internal nodes of the slicing*-tree.

8. 8 Experimental Evaluation ●Experimental setup  Subjects: 2 groups of 5 grad. students each, browse on PDAs with/without our system on proxy  Devices: HP iPAQ hx4700 Pocket PC  Test data set: 15 Web pages & 10 browsing tasks ●Experimental result  Task completion time: achieved shorter task completion time in all of the 10 tasks. Improvement: focused search tasks: 47%; reading tasks: 22.7%  Input effort: reduced # of pen moves in 9 out of 10 tasks. Improvement: focused search tasks: 50% ; reading tasks: 28.4%  Bandwidth consumption: saved bandwidth consumption in 7 out of 10 tasks, and the average saving was 18.9%.

9. 9 Conclusion ●Slicing*-tree based transformation method improves Web browsing on PDAs  Multi-level hierarchy balances fanout and height.  Horizontal and vertical scrolling is nearly eliminated.  Textually-enhanced thumbnails provide better overviews and contexts to sub-pages. Full paper available at http://www.cs.ust.hk/~xiaoxy/http://www.cs.ust.hk/~xiaoxy/