Shakespeare Statistics


The General Imposters Method and Arden of Faversham

BRD-Flagge in German     All data were generated with R Stylo. See:


In his blog "Authorship verification with the package 'stylo'" of May 30, 2018 Maciej Eder (https://computationalstylistics.github.io/blog/imposters/) described a new feature of the stylo package 'namely the General Imposters (GI) method, also referred to as the second verification system, introduced by Koppel and Winter (2014) and applied to the study of Julius Caesar's disputed writings (Kestemont et al., 2016a).' Eder then quotes the authors: "[t]he general intuition behind the GI, is not to assess whether two documents are simply similar in writing style, given a static feature vocabulary, but rather, it aims to assess whether two documents are significantly more similar to one another than other documents, across a variety of stochastically impaired feature spaces (Eder, 2012; Stamatatos, 2006), and compared to random selections of so-called distractor authors (Juola, 2015), also called 'imposters'." (Kestemont et al., 2016a: 88). In the context of the authorship attribution of the early history play The Life and Death of Jack Straw (pr. 1593) the following play texts were in the corresponding folder:
anon_arden.txt, greene_friarbb.txt, greene_orlando.txt, kyd_soliman.txt, kyd_spantrag.txt, mar_tamburlain1.txt, mar_tamburlain2.txt, shak_romjul1595.txt, shak_thnight.txt.
For each of these texts, word frequencies and the frequencies of character trigrams were examined with GI, and their number was determined with 2000. The classical delta method was used in each case, supplemented by the so-called Wurzburg distance and Ruzicka metrics. The main procedure is available via the function imposters(). It assumes that all the texts to be analyzed are already pre-processed and represented in a form of a matrix with frequencies of features (usually words). The function contrasts, in several iterations, a text in question against (1) some texts written by possible candidates to authorship, or the authors that are suspected of being the actual author, and (2) a selection of "imposters", or the authors that could not have written the text to be assessed. Consequently, a given candidate's class is assigned a score between 0 and 1. On theoretical grounds, any score above 0.5 would suggest that the authorship verification for a given candidate was successful (quote from Eder's blog). The allocation resulted in the following tabular overview:
Table 1

Values above 0.5 prove authorship, though not necessarily sole authorship. Delta and the very precise Ruzicka metrics indicate preferably William Shakespeare's authorship of Arden of Faversham (lines 3, 10, 11, and 14, 21, 22). Shakespeare's immense stylistic influence can also be seen in the "shak" columns.

Compare these evaluations with the results of Rolling Classify and of Rolling Delta.