Yet with such a visualization the main downside becomes clear: we lose context. Who are the protagonists? Who are the villains? As adjectives are separated from other concepts, we lose the ability to derive meaning. For example, a politician speaks of “taxes” frequently: but from a word cloud, it is difficult to learn whether they are positive or negative references. With these shortcomings in mind, however, historians can find utility in word clouds.

It also represents the inversion of the traditional historical process: rather than looking at documents that we think may be important to our project and pre-existing thesis, we are looking at documents more generally to see what they might be about. With Big Data, it is sometimes important to let the sources speak to you, rather than looking at them with pre-conceptions of what you might find.

In brief, they are generated through the following process. First, a computer program takes a text and counts how frequent each word is. In many cases, it will normalize the text to some degree, or at least give the user options: if “racing” appears 80 times and “Racing” appears 5 times, you may want it to register as a total of 85 times to that term.