PAIR: Pairwise Alignment for Intertextual Relations
In 2009, ARTFL celebrated an open source software release of PAIR (Pairwise Alignment for Intertextual Relations) with an alpha version of PhiloLine available for download at Google Code. PAIR is designed as powerful search tool to help scholars tackle and better understand the widespread problem of literary text reuse.
While PAIR was developed in response to the fairly specific phenomenon of similar passages across literary works, the sequence analysis techniques employed in PAIR were developed in widely disparate fields, such as bioinformatics and computer science, with applications ranging from genome sequencing to plagiarism detection. PAIR generates a set of overlapping word sequence shingles for every text in a corpus, then stores and indexes that information to be analyzed against shingles from other texts. For example, the opening declaration from Rousseau's Du Contrat Social,
"L'homme est né libre, est partout il est dans les fers. Tel se croit le maître des autres, qui ne laisse pas d'être plus esclave qu'eux,"
would be rendered in trigram shingles (with accents flattened and function words removed) as:
Common shingles across texts indicate many different types of textual borrowings, from direct citations to more ambiguous and unattributed usages of a passage. Using a simple search form, the user can quickly identify similar passages shared between different texts in one database, or even across databases, as in our Encyclopédie vs. FRANTEXT alignment. By selecting a shingle match size parameter, the user can further narrow the search results to look for shared passages of specific lengths.
Interested parties are encouraged to consult the release site for more documentation, including technical details, PhiloLine source downloads, and a freestanding Perl module.
PAIR for Subscribers
We have made three PAIR search tools available for subscribers.
The ARTFL Project Department of Romance Languages and Literatures Division of the Humanities University of Chicago 1115 East 58th Street Chicago, IL 60637 tel: 773-702-8488 | email: artfl[at]artfl[dot]uchicago[dot]edu