Wikipedia is an example of the large, collaborative, semi-structured data sets emerging on the Web. Typically, before these data sets can be used, they must transformed into structured tables via data integration. We present Vispedia, a Web-based visualization system which incorporates data integration into an iterative, interactive data exploration and analysis process. This reduces the upfront cost of using heterogeneous data sets like Wikipedia. Vispedia is driven by a keyword-query-based integration interface implemented using a fast graph search. The search occurs interactively over DBpedia’s semantic graph of Wikipedia, without depending on the existence of a structured ontology. This combination of data integration and visualization enables a broad class of non-expert users to more effectively use the semi-structured data available on the Web.