The research carried out by Education Development Center, Inc. (EDC) focused on helping middle-grades students improve reading comprehension in social studies by building word knowledge through the use of a web-based tool, Visual Thesaurus (VT). VT allows the reader to look up a word directly from a piece of electronic text. It does not directly define words; rather it presents an array of concepts that capture the varied word meanings. The features of VT align with the following e-text resources: translational, illustrative, enrichment, and collaborative. From August, 2006 to May 2007, EDC carried out a series of four brief design studies, with each one building on findings of the previous study. Read the executive summary and download the June 2007 progress report of research on the Visual Thesaurus:  Progress Report June 2007