This paper addresses the task of extracting opinions from a given document collection. Assuming that an opinion can be represented as a tuple Subject, Attribute, Value , we propose a computational method to extract such tuples from texts. In this method, the main task is decomposed into (a) the process of extracting Attribute-Value pairs from a given text and (b) the process of judging whether an extracted pair expresses an opinion of the author. We apply machinelearning techniques to both subtasks. We also report on the results of our experiments and discuss future directions.