Used to compare the style of multiple texts with a principal text, rolling deltas allow digital humanist to analyse an author’s style in relation to his own work or another author. The relationship between the main text’s and the other texts’ style is displayed as a graph, as shown below.For this example I used a rolling delta delta graph to show how similar Shakespeare’s comedies are to sections of another Shakespearean comedy, Much Ado About Nothing. The horizontal axis represents sections of Much Ado About Nothing, which has been split into 5000 word sections with 1000 word steps in each section. Each individual section is then compared against the entirety of each comparative text; the level of similarity between the section of Much Ado and the comparative text is plotted against the vertical axis.
The resulting graph visualises level of stylistic similarity between Shakespeare’s comedies, using Much Ado as the base line for comparisons. It is at this point that knowing the texts you are using comes into play in order to interpret the graph. For example, The Taming of the Shrew is incredibly similar to a section of Much Ado where Beatrice, one of the female protagonists, is at her most shrew-like. This makes sense as Beatrice is at her most similar to Katherina, The Taming of the Shrew’s protagonist, at the beginning of Much Ado.
To conclude, a rolling delta graph is a visual interpretation of the similarities and differences between a principal text and multiple comparative texts. However, interpreting the resulting graph requires a knowledge of the texts’ content so it is advisable to choose texts you have done a close reading of previously.