From an Item in the Library of Congress Labs Newsletter (April 2021):
Ed Sperr, one of the winners of the 2018 LC Labs Congressional Data Challenge, recently created a tool to visualize term frequency [Collection View] in LC collections using the loc.gov API. You can search for a term and see its frequency by publication year and type of material, and compare search terms to each other.
More From the Collection View Website:
Collection View is in part an extension of my [Ed Sperr] work on Search Workbench. Just as that project enables one to visualize PubMed results, Collection View allows you to visualize your Library of Congress searches so that you can get a better sense of what they are doing. Importantly, you can also directly compare searches to one another — facilitating the process of fine-tuning a search strategy.
How it works
Collection View summarizes your search results by plotting them on a couple of different data visualizations. In the first, raw numbers for each format are visualized as a stacked bar graph. In the second, searches using Boolean logic are visualized using a Venn diagram. This view is also available when you’re comparing multiple searches. Finally, the proportions of items in your search for each format and each century are compared to the baselines for the collection as a whole.
Direct to Collection View
See Also: Visualizing PubMed
A group of tools from Ed Sperr