  Current text visualization techniques typically provide overviews of document
content and structure using intrinsic properties such as term frequencies,
co-occurrences, and sentence structures. Such visualizations lack conceptual
overviews incorporating domain-relevant knowledge, needed when examining
documents such as research articles or technical reports. To address this
shortcoming, we present ConceptScope, a technique that utilizes a domain
ontology to represent the conceptual relationships in a document in the form of
a Bubble Treemap visualization. Multiple coordinated views of document
structure and concept hierarchy with text overviews further aid document
analysis. ConceptScope facilitates exploration and comparison of single and
multiple documents respectively. We demonstrate ConceptScope by visualizing
research articles and transcripts of technical presentations in computer
science. In a comparative study with DocuBurst, a popular document
visualization tool, ConceptScope was found to be more informative in exploring
and comparing domain-specific documents, but less so when it came to documents
that spanned multiple disciplines.
