1. Supporting document use through interactive visualization of metadata Visual Interfaces to Digital Libraries JCDL 28/06/2001 Mischa Weiss-Lijn

2. Why support within- document search?  DL’s need to support users in satisfying their information needs (Borgman 1996)  Information needs are met at a sub-document level –“[Digital Library] users […] want to retrieve information rather than documents per se.” (Van House 1995) –Adler et al (1998) found that document use often involved goal-directed search where users only make use of small portions of documents

3. What is different about within-document visualization?  Much between-document visualization supports browsing, contextualization, and query development –Corpus summarization – clustering derived document landscapes (i.e. cartia’s themscape, kohonen maps)

4. What is different about within-document visualization? –Classification hierarchy visualization (cone tree’s, Galaxy of news) –Co-citation visualization

5. What is different about within-document visualization?  Document use often involves multiple, rapid, goal-directed searches to support concurrent tasks such as writing, form-filling, discussion etc. Adler et al (1998)

6. What is different about within-document search?  With within-document search an important requirement is to support rapid goal-directed search… –Visualization of a documents contents should focus on rapidly satisfying focused information needs

7. Paragraph-level document metadata as a basis for document visualization –Paragraph-level metadata:  Describes content  Can use the same ‘local’ language as user information needs.  Describes the location and extent of content  Can be aggregated at multiple levels  Can be smoothing integrated with current DL search technology

8. The Technology  Gridvis emerged from an iterative process of design, prototyping and evaluation

9. Experimental evaluation: methodology –Set-up  12 subjects  4 documents. –Task  For each document the subject was asked to rapidly find the paragraphs which contained answers to 3 questions.  Gridvis for 2 documents  Conventional scroll bar used for other 2 docs.

10. Experimental evaluation: results –No statistically significant difference in performance -  Is paragraph-level metadata inadequate for the task? –Qualitative analysis  Objective - Why was Gridvis performance poor?  Developed a classification of user strategies, and used them to classify user actions  Found that: –Subjects seldom capitalize on information given by the visualization –Exhaustive application of strategies increased recall and precision

11. Experimental evaluation: results  So… –The application could potentially deliver better performance –The interface needs to encourage the use of applicability and co-occurrence information Partial automation of co-occurrence strategy Eliminate need for horizontal scrolling Make relevant paragraphs easier to locate

12. Conclusions  Research on DL visualization should consider how to support document use in general, and goal-directed search in particular  Visualizations of paragraph level metadata may provide a basis for such support