Friday, January 21, 2011
Comment for readings of the second week
I have read the paper "Automatic Metaphor Interpretation as a Paraphrasing Task". For the focused paper, I think it has done a good job covering the features and resources needed. For the selected paper, as the author is the same person as focused paper, the process of metaphor processing is divided to two sub-tasks and this paper is only tackling the metaphor interpretation, in which case the instance has already been identified as a metaphor, and the system simply needs to find out the most appropriate substitute for the metaphor verb. Although the task is not exactly Word Sense Disambiguation (WSD), this set-up of task seems to be doing WSD in one of its easy cases, and therefore has made the task much easier than WSD. First of all, identifying the metaphor itself is non-trivial. Actually, if we can successfully identify the metaphors, we are already beating the most frequent sense baseline (MFS), which is already state of art. Whenever the metaphor is identified, it is basically saying that most frequent sense, which in general is not metaphorical, is pruned out from the consideration. This makes the selection of the sense among the remaining senses much easier because the distribution of word sense is usually highly skewed to the MFS, and once it is removed, the prediction is much easier. Also the instances of metaphor that are chosen demonstrate much stronger constraints of the context (in this case selection restriction), and this makes the task even easier. Finally the evaluation used is based on substitutes, not WordNet synonyms, which could be much more fine grained. Despite these, I do think the paper has done a good job formulating the problem and the high presence of the metaphor does justify the task and also the identification of the metaphor can from a different angle make the general WSD task easier.