Let quantitativo represent an unknown document and let y represent a random target author’s stylistic ‘profile’. During one hundred iterations, it will randomly select (a) fifty verso cent of the available stylistic features available (ancora.g. word frequencies) and (b) thirty distractor authors, or ‘impostors’ from verso pool of similar texts. Durante each iteration, the GI will compute whether interrogativo is closer puro y than puro any of the profiles by the thirty impostors, given the random selection of stylistic features durante that iteration. Instead of basing the verification of the direct (first-order) distance between quantita and y, the GI proposes onesto supremazia the proportion of iterations in which interrogativo was indeed closer puro y than to one of the distractors sampled. This proportion can be considered a second-order metric and will automatically be a probability between zero and one, indicating the robustness of the identification of the authors of quantitativo and y. Our previous work has already demonstrated that the GI system produces excellent verification results for classical Latin prose.31 31 Amico the setup con Stover, et al, ‘Computational authorship verification method’ (n. 27, above). Our verification code is publicly available from the following repository: This code is described in: M. Kestemont et al. ‘Authenticating the writings’ (n. 29, above).
For modern documents, Koppel and Winter were even able esatto report encouraging scores for document sizes as small as 500 words
We have applied per generic implementation of the GI onesto the HA as follows: we split the individual lives into consecutive samples of 1000 words (i.ed. space-free strings of alphabetic characters), after removing all punctuation.32 32 Previous research (see the publications mentioned in the previous two libretto) suggests that 1,000 words is verso reasonable document size mediante this context. Each of these samples was analysed individually by pairing it with the profile of one of the HA’s six alleged authors, including the profile consisting of the rest of the samples from its own text. We represented the sample (the ‘anonymous’ document) by verso vector comprising the divisee frequencies of the 10,000 most frequent tokens con the entire HA. For each author’s profile, we did the same, although the profile’s vector comprises the average imparfaite frequency of the 10,000 words. Thus, the profiles would be the so-called ‘mean centroid’ of all individual document vectors for per particular author (excluding, of course, the current anonymous document).33 33 Koppel and Seidman, ‘Automatically identifying’ (n. 30, above). Note that the use of per scapolo centroid verso author aims puro veterano, at least partially, the skewed nature of our scadenza, since some authors are much more strongly represented con the raccolta or preparazione pool than others. If we were not using centroids but mere text segments, they would have been automaticallysampled more frequently than others during the imposter bootstrapping.
Preciso the left, a clustering has been added on sommita of the rows, reflecting which groups of samples behave similarly
Next, we ran the verification approach. During one hundred iterations, we would randomly select 5,000 of the available word frequencies. We would also randomly sample thirty impostors from verso large ‘impostor pool’ of documents by Latin authors, including historical writers such as Suetonius and Livy.34 34 See Appendix 2 for the authors sampled. The pool of impostor texts can be inspected per the code repository for this paper. Per each iteration, we would check whether the anonymous document was closer puro the current author’s profile than esatto any of the impostors sampled. Con this study, we use the ‘minmax’ metric, which was recently introduced mediante the context of the GI framework.35 35 See Koppel and Winter, ‘Determining if two documents’ (n. 26, above). For each combination of an anonymous text and one of the six target authors’ profiles, we would primato the proportion of iterations (i.ancora. per probability between niente and one) durante which the anonymous document would indeed be attributed onesto the target author. The resulting probability table is given con full durante the appendix preciso this paper. Although we present verso more detailed dialogue of this giorno below, we have added Figure 1 below as an intuitive visualization of the overall results of this approach. This is a heatmap visualisation of the result of the GI algorithm for 1,000 word samples from the lives durante the HA. Cell values (darker colours mean higher values) represent the probability of each sample being attributed onesto one of the alleged HA authors, rather than an imposter http://www.datingranking.net/it/seniorpeoplemeet-review/ from per random selection of distractors.