Authorship Attribution

1
Authorship Attribution

• Erik Goldman Abel Allison

2
Problem

• Definition Identification of the author of an
  anonymously written document given a set of
  candidate authors.
• Applications
• Historical Scholarship
• Investigative Forensic Identification
• Example Fake Steve Jobs

3
Related Work

• Support Vector Machine methods
• Diederich et al. (2003)
• Document prototypes (interesting documents or
  part of extracted, salient texts, to match with a
  document database
• Visa et al. (2001)
• Numerical method of fractional counts
• Burrel and Rousseau (1995)

4
Approach

1. For each work in the training set, count various
   feature data (more on features next slide), store
   as histograms.
2. Input unknown document and make same counts.
3. Compare the histograms of each author with those
   of the unknown. Each feature contributes a
   weighted vote.
4. Choose author with the highest comparison score

5
Metrics

• Limit Word Frequency-Words frequently used by the
  author across multiple works.
• Grapheme Frequency-Counts of alphanumeric and
  symbol characters.
• Part-of-speech Bigram Frequency -
• Preterminal Tag Bigram Model -

6
Histogram Comparisons

• Two Methods Used
• Chi-Squared Metric
• Difference Formula similar to the Chi-Squared
  formula, except accounts for sparsity of bi-gram
  counts by normalizing them with respect to the
  average counts

7
Tests

• Used the power set of our set of authors.
• For each element in the power set, we ran our
  tests using each of the authors as the unknown
  and recorded the results.

8
Results