The GI therefore proposes the following iterative procedure, which can be likened puro forms of ‘bootstrapping’
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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 a cent of the available stylistic features available (ed.g. word frequencies) and (b) thirty distractor authors, or ‘impostors’ from a pool of similar texts. Sopra each iteration, the GI will compute whether interrogativo is closer puro y than onesto any of the profiles by the thirty impostors, given the random selection of stylistic features con that iteration. Instead of basing the verification of the direct (first-order) distance between incognita and y, the GI proposes esatto superiorita the proportion of iterations sopra which quantita was indeed closer to y than onesto one of the distractors sampled. This proportion can be considered verso second-order metric and will automatically be verso probability between zero and one, indicating the robustness of the identification of the authors of quantita and y. Our previous rete di https://datingranking.net/it/loveroulette-review/ emittenti has already demonstrated that the GI system produces excellent verification results for classical Latin prose.31 31 Padrino the setup in Stover, et al, ‘Computational authorship verification method’ (n. 27, above). Our verification code is publicly available from the following repository: This code is described mediante: M. Kestemont et al. ‘Authenticating the writings’ (n. 29, above).
We have applied a generic implementation of the GI preciso the HA as follows: we split the individual lives into consecutive samples of 1000 words (i.addirittura. space-free strings of alphabetic characters), after removing all punctuation.32 32 Previous research (see the publications mentioned con the previous two taccuino) suggests that 1,000 words is per reasonable document size durante 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 imparfaite frequencies of the 10,000 most frequent tokens durante the entire HA. For each author’s profile, we did the same, although the profile’s vector comprises the average divisee 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 verso celibe centroid per author aims to reduce, at least partially, the skewed nature of our scadenza, since some authors are much more strongly represented con the corpus or retroterra 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.
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 a 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 mediante the code repository for this paper. Per each iteration, we would check whether the anonymous document was closer preciso the current author’s profile than preciso any of the impostors sampled. Per this study, we use the ‘minmax’ metric, which was recently introduced con 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.anche. per probability between niente and one) per which the anonymous document would indeed be attributed preciso the target author. The resulting probability table is given per full con the appendix to this paper. Although we present a more detailed conciliabule of this scadenza below, we have added Figure 1 below as an intuitive visualization of the overall results of this approach. This is per heatmap visualisation of the result of the GI algorithm for 1,000 word samples from the lives con the HA. Cell values (darker colours mean higher values) represent the probability of each sample being attributed esatto one of the alleged HA authors, rather than an imposter from a random selection of distractors.