Precision vs. Recall Suppose we have a search engine that performs unranked Boolean retrieval over a collection of 1,000 documents. A user has an information need for which there are 30 relevant documents and enters a Boolean query that returns 300 results. Suppose that the Boolean retrieval is associated with the following contingency table. Every document in the collection falls into one of the cells in the table. Relevant Not Relevant Retrieved Not Retrieved 30 0 270 700 (a) Compute precision and recall for this particular retrieval. [10 points]