CREDO is an easy-to-use tool for preliminary research. Search in hundreds of encyclopedias, dictionaries, thesauri, quotations, and subject-specific titles, as well as over 200,000 images and audio files and nearly 100 videos.
NOTE: If the search box is not working ... use the direct connection link.
Wikipedia provides crowdsourced information on many topics ... which can be a good source of common knowledge ... but one must be very careful to critiique the accuracy and reliability of such information. The resources listed above do have guaranteed authority and accuracy.
Consider using the Wolfram Alpha search engine Examples sections for overviews of disciplines ... with data and explanations of the underlying equations, principles, and conditions.
The library provides access to the Simply Map tool that allows researchers to mine U.S. census data and sets of business data in order to generate maps or build data sets that can be exported into other tools such as Excel, SPSS, and SAS for further manipulation. See a brief video demonstrating a simple mapping of one census variable.
In addition, researchers can search for data sets using Databib - a searchable catalog / registry / directory / bibliography of research-data repositories. These data sets must be imported (in some cases after format manipulation) into data tools such as SPSS and SAS. For additional information about Data support, see the Purdue University Data site.