Visualization of search results from the World Wide Web

English) This thesis explores special forms of presentations of search results from the World Wide Web. The usage of Information Visualization methodologies is discussed as an alternative to the usual arrangement in form of a static HTML-list. The thesis is structured into four main parts. The first part deals with information seeking. It presents ideas from the literature on how to structure the information seeking process and some results from studies of how people search the Web. For the second part visualization ideas, metaphors, techniques, components and systems have been collected. The overview focuses on the visualization of queries or query attributes, document attributes, and interdocument similarities. The reference model for visualization from [Card, Mackinlay, Shneiderman 1999] is used to discuss differences between certain techniques. Visualization components from a number of areas, usage scenarios, and authors are presented using a consistent search example wherever possible. The part about Information Visualization also includes a discussion of multiple coordinated views and some results from empirical evaluations of visualizations by other authors. The third, empirical part of the thesis presents the results of an evaluation of five different user interface conditions of a local meta search engine called INSYDER. An overview covering the INSYDER project in general, the system architecture, and the development of the implemented visualization ideas is included. In a test with 40 users effectiveness, efficiency, expected value, and user satisfaction were measured for twelve tasks. Evaluated user interface conditions were HTML-List, ResultTable, ScatterPlot plus ResultTable, BarGraph plus ResultTable, and SegmentView plus ResultTable. The SegmentView included TileBars and StackedColumns variants. The traditional presentation in the form of an HTML-List performed best in terms of effectiveness and efficiency. In contrast to this, the users preferred the ResultTable and the SegmentView. The last section of the thesis consists of a summary and an outlook.