No source: created in electronic format.
In the literary world, authorship of great novels is like writing a great piece of music; while there may never be a perfect way to determine if someone wrote a particular work or not, equations and algorithms have been developed in information theory and statistics to help those trying to discover the true authorship of contested written works. Because no method is perfect, using a set of methods on the same works can be used to give high probabilities of authorship. The JGAAP system houses a collection of methods such as Histogram Distance and Manhattan Distance and event sets such as word bigrams and character trigrams to allow users to perform multiple tests on contested works to see if the supposed author is actually the author by comparing samples from both the contested author and other possible authors.
We apply this framework and show a notable discontinuity in the authorial style
of the novel El Ingenioso Hidalgo don Quijote de la
Mancha, better known as Don Quijote (or Don Quixote).
While there have been skeptics and scholars alike that have doubted Miguel de
Cervantes Saavadre's true authorship of the entirety of Don Quijote, no one had tested whether or not Cervantes was in fact
the true author of the whole of Don Quijote. The purpose
of using the JGAAP system was to either give merit to or disprove this theory.
By comparing to other authors who wrote works at about the same time Don Quijote was written, the JGAAP system would test to
see if the text that Cervantes supposedly wrote was closer to the first volume
of Don Quijote or closer to other authors of the same
time period. If a definitive break could be established between where the
program attributed Cervantes as the author and where it did not, that would
suggest either a major style shift or the presence of another author different
from Cervantes, while no break at all would suggest that Cervantes was in fact
the true author of the second volume of Don Quijote,
assuming that he was also the author of the first volume.
For this authorship attribution, the program JGAAP 4.0 was downloaded from http://www.jgaap.com, developed by Patrick Juola at Duquesne
University. The Don Quijote text used was acquired from
Project Gutenburg at http://www.projectgutenburg.org. The
full text of Don Quijote was then stripped of the introductions and separated
into chapters by volume. The first volume was then set as the basis for Miguel
de Cervantes' original authorship. Every third chapter, starting with
chapter three, was used as the base case for Cervantes' work. Two other
authors used for comparison, Fransisco de Quevedo and Mateo Alemán, were also
used. Quevedo's, Historia de la vida del Buscón, llamado
Don Pablos, ejemplo de vagamundos y espejo de tacaños and Alemán's
Guzmán del Alfarache were also taken from Project Gutenburg and broken
into roughly the same number of chapter-type sections as the number of chapters
used for Cervantes' Don Quijote. In order to make
sure that Cervantes' was actually the author of volume one of Don Quijote, every chapter not used in the base case was
compared to the base chapters, Quevedo's work, and Alemán's work. Each
test used JGAAP's Normalize Whitespace, Strip Punctuation, and Unify Case
canonicizers on all of the documents. Five event sets - Word, WordBiGram,
WordTriGram, WordTetraGram, and Word Length - were all paired with nine analysis
methods - Camberra Distance, Cosine Distance, RN Cross Entropy, Histogram
Distance, Kullback Leibler Divergence, Levenshtein Distance, Manhattan Distance,
KS Distance, and Naive Bayes Classifier, for a total of 45 unique event
set-analysis methods. Once the first volume of Cervantes' work was
confirmed to be uniformly Cervantes', volume two of Don
Quijote was tested in the same manner as the first volume in order to
provide an accurate analysis.
We apply a mixture-of-experts approach to the evaluation of authorship. Each
different method is treated as a single "expert" in different aspects
of authorial style, and permitted to vote on who (among the candidates) is the
author of any specific fragment. If all 45 test "experts" vote on
Cervantes, we consider this to be strong evidence supporting his authorship,
while if only 5 or so of the 45 consider Cervantes to be the most likely author,
we consider this to be evidence against.
As a result of the analysis on the second volume of Don
Quijote, the JGAAP program indicated that starting at chapter 6
Cervantes was not the author. Out of the 45 tests run on each chapter, the
chapters in the first volume had a mean of 37.54 occurrences of Cervantes as the
author with a standard deviation of .852. The first five chapters of the second
volume had a mean of 36.50 occurrences of Cervantes as the author with a
standard deviation of 1.517. Chapters 6-74 of the second volume, however, had a
mean of 4.90 occurrences of Cervantes as the author with a standard deviation of
1.436. This radical shift in authorship means either Cervantes completely
shifted his writing technique or he did not write the latter 69 chapters of the
second volume of Don Quijote.
While there are people who are skeptic about the authorship of Don Quijote, nothing up until now has given those claims any grounds
other than speculations based on inconsistencies in the text. Although this
analysis does not guarantee that Cervantes did not write the last 69 chapters of
the second volume, it does make the probability of that claim much greater.
This, in part, is due to the fact that none of the tests in JGAAP has been
tested enough to show that it will work for all documents. As further analysis
of the methods continues, the results of the tests used in this authorship
attribution will most likely validate these results. As tests and methods prove
to not work, the analysis will be redone with these tests omitted from the
analysis giving a more accurate result.