I used to work in machine translation, about 15 years ago. At the time, one of the big things they were working on was an improvement to the contextual inferenc

I used to work in machine translation, about 15 years ago. At the time, one of the big things they were working on was an improvement to the contextual inferences. The prior versions were able to consider context within a single sentence, and input documents could be tagged with a subject area, so the system would know to resolve ambiguities in favor of, say, medical terms. The best examples of this, I thought, were the following passages: Yesterday I went to the symphony. The sound was beautiful. versus Yesterday I went to Long Island. The sound was beautiful. In the first passage, sound refers to an auditory experience; in the second, it refers to a body of water. Within the sentence "The sound was beautiful", there's no way to know which to use, so one must look to surrounding information to make a guess. But I've given a short and clear example; anyone can see the right solution. But in real-life usage it's frequently unclear.