WebTrails: Enhancing Internet Navigation and Search

1. WebTrails Jure Leskovec University of Ljubljana, Slovenia Internship at MSR (Aug 1 – Sept 31, 2001)

2. Outline • Problem statement • Our approach • Demo

3. A B C D E F Problem 1: History Navigation • Insufficient support for navigation over seen pages • One step linear navigation (back/forward) • Lost parts of navigation (inaccessible pages)

4. Problem 2: Search • Poor search facility in Internet Explorer • No visual clues • Inflexible results sorting • No navigation information

5. IE History Navigation

6. IE History Search

7. Objectives • Enhance the history with navigation information • Provide easy access to the seen pages • Recent history in-session navigation support tool • Whole history search over all seen pages

8. Proposed Solution • Easy access to a page seen in the current browsing session - Session Navigator • Visual clues – Thumbnails of accessed pages • Navigation Trails -Grouping pages based on navigation • Whole history search: • Time query • Text query (content, query, link) • Colour scheme (position of colours on the page)

9. WebTrails • Definition: Sequence of traversed pages started by • entering a search query • typing a URL and generated by • following links • using back/forward buttons • using the Session Navigator.

10. Captured Data • For each page the WebTrail contains: • Page URL • Body text • Page type • Accessed by following a link • Opened in a new window • Typing in a URL • Typing a search query (search result page) • Back/forward navigation • Time • Referring page (parent)

11. Session Navigator • Trail building and GUI presentation • Trail building and GUI presentation Navigation Tree Linear Trail A A A B B C C A D D E E D F B D E • Flattening the graph to a linear sequence of tree branches • Time ordered • Cursor indicating the current page F C

12. Session Navigator (2) • Trail usage • Reviewing seen pages • Random access to a page to continue browsing (add already viewed page if navigating further away from the page)

13. WebTrail Graph

14. Search • Search over colour schemes of thumbnail images • Assumption: people remember position of highly distinct or predominant colours on the page • Visual clues – Thumbnails and WebTrails in the search results

15. Thumbnail Analysis • Partitioning thumbnails into regions • Assigning a single colour per region • Histogram analysis • Colour clustering

16. Histogram colour merging Body Right Left

17. Green Blue Red Colour Clustering • Colour Spaces • 3d space – RGB, HSL, CIELab

18. Green Blue Red Color Similarity RGB Space RGB color space, Euclidean distance 60

19. Green Blue Red Colour Clustering (2) RGB Space • Problem: Define colour distance measure so that colours similar by human perception are close in distance

20. RGB HSV Green Blue Red Colour set Colour Clustering (2) RGB Space Saturation • Solution: 2 step colour merging • Conservative merging in RGB space • Further merging in HSV space Colours in the union of two neighbourhoods are merged Value Hue HSV Space

21. Colour Clustering (3) Benefits: • Flexible colour palette selection • Applying different threshold on the distance

22. Colour Palettes • Automatically generated from the collection of thumbnails 15 colour palette 25 colour palette

23. Colour Clustering (3) Benefits: • Flexible colour palette selection • Applying different threshold on the distance • Simplified description of the page • By reducing the number of colours on the page representation • Human friendly colour distinction • Reducing the fine variability in colours

24. Thumbnail Clustering • Clustering thumbnail colour schemes • Hierarchical clustering based on colour position • Off-line (at the moment) • Useful for • Query by example • Browsing through navigation history

25. WebTrails 0.1 DEMO