Anaphora resolution in Machine Translation

Anaphora resolution is vital in Machine Translation It is essential to resolve the anaphoric

relation when translating into languages that mark the gender of pronouns from languages that do not

It is essential to resolve the anaphoric relation between language pairs that contain gender discrepancies

Example The monkey ate the banana because it was

hungry. The monkey ate the banana because it was ripe. The monkey ate the banana because it was tea

time. Le singe a mangé la banane parce qu’il avait

faim Le singe a mangé la banane parce qu’elle était

mûre Le singe a mangé la banane parce que c’ était

l’heure du dîner.

Status quo Majority of MT systems do not attempt to

resolve anaphora Translation adds a further dimension to

the complexity of anaphora resolution The reference to a discourse entity

encoded in a source language anaphor by the speaker (or writer) has not only to be identified by the hearer (translator or translation system) but also re-encoded (generated) in a different language.

Additional complexity due to… gender discrepancies across

languages number discrepancies of words

denoting the same concept discrepancies in gender inheritance

of possessive pronouns discrepancies in target language

anaphor selection

Gender discrepancies across languages

Je prends le livre. Il est bon. Ich nehme das Buch. Es ist gut.

Number discrepancies of words denoting the same concept Die Informationen sind falsch. Sie

verursachten aber eine Panik. The information is wrong. But it

caused a panic. The police are coming. They are

just in time. Die Polizei kommt gerade. Sie

kommt gerade noch rechtzeitig.

Discrepancies in gender inheritance of possessive pronouns

Jacques a détruit sa voiture. Jacques hat sein Auto zerstört.

Discrepancies in target language anaphor selection Translation of pronominal anaphors In the majority of language pairs and

cases the pronouns in the source language are translated by target language pronouns which correspond to the antecedent of the anaphor but there are some exceptions.

Discrepancies in target language anaphor selection (2) English-to-Malay translation: there is a tendency

to replace it with its antecedent. English to Spanish (or Portuguese, Italian,

Bulgarian, Korean, Japanese, Thai…): pronouns may simply be omitted (zero anaphors) in the target language

English-to-Korean translation: pronouns (i) can be omitted elliptically, (ii) translated by a definite noun phrase, (iii) by their antecedent, or (iv) by one or two possible Korean pronouns, depending on the syntactic information and semantic class of the noun to which the anaphor refers ([Mitkov et al. 94]).