  This research offers a new interdisciplinary approach to the field of
Linguistics by using Computational Linguistics, NLP, Bayesian Statistics and
Sociolinguistics methods. This thesis investigates word order change in
infinitival clauses from Object-Verb (OV) to Verb-Object (VO) in the history of
Latin and Old French. By applying a variationist approach, I examine a
synchronic word order variation in each stage of language change, from which I
infer the character, periodization and constraints of diachronic variation. I
also show that in discourse-configurational languages, such as Latin and Early
Old French, it is possible to identify pragmatically neutral contexts by using
information structure annotation. I further argue that by mapping pragmatic
categories into a syntactic structure, we can detect how word order change
unfolds. For this investigation, the data are extracted from annotated corpora
spanning several centuries of Latin and Old French and from additional
resources created by using computational linguistic methods. The data are then
further codified for various pragmatic, semantic, syntactic and sociolinguistic
factors. This study also evaluates previous factors proposed to account for
word order alternation and change. I show how information structure and
syntactic constraints change over time and propose a method that allows
researchers to differentiate a stable word order alternation from alternation
indicating a change. Finally, I present a three-stage probabilistic model of
word order change, which also conforms to traditional language change patterns.
