1) All previous Japanese sense-tagged corpora were from newspaper articles, while sense-tagged corpora have been constructed in English on balanced corpora, such as Brown corpus and BNC corpus. The first balanced corpus of contemporary written Japanese (BCCWJ corpus) is now being constructed as part of a national project in Japan [Maekawa, 2008], and we are now constructing a sense-tagged corpus on it. Therefore, the task will use the first balanced Japanese sense-tagged corpus.

2) In previous WSD tasks, systems have been required to select a sense from a given set of senses in a dictionary for a word in one context (an instance). However, the set of senses in the dictionary is not always complete. New word senses sometimes appear after the dictionary has been compiled. Therefore, some instances might have a sense that cannot be found in a set in the dictionary. The task will take into account not only the instances having a sense in the given set but also the instances having a sense that cannot be found in the set. In the latter case, systems should output that the instances have a sense that is not in the set.