Teasing Out Authorship and Style with T-tests and Zeta
David L. Hoover · DH · 2010
Most computational stylistics methods were developed for authorship attribution, but many have also been applied to the study of style. Investigating Wilkie Collin's Blind Love (1890), left unfinished at his death and completed by Walter Besant from a long synopsis and notes provided by Collins, requires both authorship attribution and stylistics. External evidence indicates that Besant took over after chapter 48 (Collins 2003), which provides an opportunity to test whether Besant was successful in matching Collins's style and to investigate the styles of Collins and Besant. This divided novel also facilitates the comparison of two computational methods: the T-test and Burrows's Zeta. The t-test is a well-studied method for determining the probability of a difference between two groups arising by chance (a classic use in authorship and stylistics is Burrows 1992.) Here I use t-tests to identify words used very differently by Collins and Besant. After showing that those word frequencies accurately identify the change of authorship, I examine the words themselves for stylistically interesting characteristics. I created a combined word frequency list for four novels by Besant and three by Collins, then deleted words occurring only once or twice, personal pronouns (too closely related to the number and gender of characters), all words with more than 90% of their occurrences in one text (almost exclusively proper names), and words limited to one author (required for t-testing). I divided the novels into 167 4,000-word sections, and performed t-tests for the remaining 6,600 words (using a Minitab macro). I cleaned up the results and sorted them on the p value in Excel (with another macro), and retained only the 1719 words with p < .05, about 1,000 for Collins and 700 for Besant