1. ManyEyes. After logging in to ManyEyes we will create four visualizations using one State of the Union Address.
Try Word Cloud Generator, Word Tree, Phrase Net, and Tag Cloud using just one text (e.g. 2008).
Next, we will prepare a special file that, in ManyEyes, allows us to compare two texts using the Tag Cloud.
You might for example try comparing Geoge W. Bush (2008) with Barack Obama (2009).
( Instructions for preparing the files are here. )
We could, of course, use ManyEyes to compare four of Bush's speeches with four of Obama's, but we would not be able to view each of those eight texts individually. The Tag Cloud only allows a comparison of two texts: all of Bush's speeches with all of Obama's.
2. Voyant. Voyeur accepts a URL (of a web-based text), or uploaded files as plain-text, HTML, XML, and (some) PDFs.
Prepare the texts: You can download this zipped file, unzip it, and upload each of the eight files into Voyant.
Voyant will present the texts in the order you upload them.
You will see something like this, and be able to compare words across all eight files.