ABSTRACT
In this chapter, we discuss the work done on automatic alignment of parallel texts for various purposes. Fundamentally, an alignment algorithm accepts as input a bitext and produces as output a bisegmentation relation that identifies corresponding segments between the texts. A bitext consists of two texts that are translations of each other.∗ Bitext alignment fundamentally lies at the heart of all data-driven machine translation methods, and the rapid research progress on alignment since 1990 reflects the advent of statistical machine translation (SMT) and example-based machine translation (EBMT) approaches. Yet the importance of alignment extends as well to many other practical applications for translators, bilingual lexicographers, and even ordinary readers.
