Collection View helps you explore your library's collections (in this case, the Library of Congress) by graphically summarizing your search results. Enter any valid LoC web search and you'll see it presented in a few different ways...
Want to see what types of materials you can find for a given search? The number of items of each format found is represented by a compact visualization. In this example, the results for 'viruses.'
Want to see how the parts of a complex search interact? Use Boolean logic, and you’ll get a Venn diagram in return. For example, here are the results for 'death AND taxes.'
Curious about how the proportion of different items for a search compare to those of the collection as a whole? A bar graph will show you that comparison for each format. In this example, those results for 'war.'
That same technique can be used to compare search result proproportions by century as well. In this example, those results for 'sputnik.'
If you want to explore different search strategies, you can directly compare them to one another in order to zero-in on exactly the terms you want to use. For example, here is the comparison between searches for 'popcorn' and 'popped corn.' (more)