In this section, we briefly describe the information domains on which our test studies are based and the usage of our prototype systems. In Section 5, we will further demonstrate the usage of the prototypes in these domains, and at the same time, illustrate the principles behind how the spreadsheet paradigm facilitates information visualization tasks. The three domains are molecular biology, time-series matrix visualization, and algorithm visualization. Each of these domains illustrates specific problems we encounter in information visualization analysis tasks. By using a task-centered approach, we show concretely how the visualization spreadsheet enables users to solve problems in information visualization.