Supporting document use through interactive

visualization of metadata

Visual Interfaces to Digital Libraries

JCDL 28/06/2001

Mischa Weiss-Lijn

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

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)

What is different about within-document visualization?

– Classification hierarchy visualization (cone tree’s, Galaxy of news)

– Co-citation visualization

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)

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

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

The Technology

Gridvis emerged from an iterative process of design, prototyping and evaluation

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.

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

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

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