Translation alignment is an essential task in Digital Humanities and Natural
Language Processing, and it aims to link words/phrases in the source
text with their translation equivalents in the translation. In addition to
its importance in teaching and learning historical languages, translation
alignment builds bridges between ancient and modern languages through
which various linguistics annotations can be transferred. This thesis focuses
on word-level translation alignment applied to historical languages in general
and Ancient Greek and Latin in particular. As the title indicates, the thesis
addresses four interdisciplinary aspects of translation alignment.
The starting point was developing Ugarit, an interactive annotation tool
to perform manual alignment aiming to gather training data to train an
automatic alignment model. This effort resulted in more than 190k accurate
translation pairs that I used for supervised training later. Ugarit has been
used by many researchers and scholars also in the classroom at several
institutions for teaching and learning ancient languages, which resulted
in a large, diverse crowd-sourced aligned parallel corpus allowing us to
conduct experiments and qualitative analysis to detect recurring patterns in
annotators’ alignment practice and the generated translation pairs.
Further, I employed the recent advances in NLP and language modeling to
develop an automatic alignment model for historical low-resourced languages,
experimenting with various training objectives and proposing a training
strategy for historical languages that combines supervised and unsupervised
training with mono- and multilingual texts. Then, I integrated this alignment
model into other development workflows to project cross-lingual annotations
and induce bilingual dictionaries from parallel corpora.
Evaluation is essential to assess the quality of any model. To ensure employing the best practice, I reviewed the current evaluation procedure, defined
its limitations, and proposed two new evaluation metrics. Moreover, I introduced a visual analytics framework to explore and inspect alignment gold
standard datasets and support quantitative and qualitative evaluation of
translation alignment models. Besides, I designed and implemented visual
analytics tools and reading environments for parallel texts and proposed
various visualization approaches to support different alignment-related tasks
employing the latest advances in information visualization and best practice.
Overall, this thesis presents a comprehensive study that includes manual and
automatic alignment techniques, evaluation methods and visual analytics
tools that aim to advance the field of translation alignment for historical
languages
