Negative effects
Nevertheless, using TM tools can also have negative effects on translation quality. This is due to the way in which texts are displayed in the editor of the TM system. It can lead to a strong tendency towards sentence-by-sentence translation without taking into account the context of the individual segments.
Ambiguities
In the case of ambiguities or pronominalisation in the source text, 100%-matches might lead to wrong translations. Consider, for example, the translation of the English sentence "Windows finds it for you" in two different contexts (1) "You do not remember where the text is", and (2) "You do not remember where the document is". The segment will be considered a 100%-match by a TM tool, although in many target languages the pronoun "it" has to be translated differently.