Summarization typically strives to reduce the set of information to be examined by a factor of 10. We will now look at this process as it could be assembled today. Information retrieval is a relatively mature technology, reflected in a highly successful commercial market. Information retrieval has been an active field of research for decades. But despite the successes, it remains the case today that on formal evaluations measured by precision and recall, the best retrieval systems perform only modestly well.
Precision measures the fraction of materials retrieved that are actually relevant to the query.
Recall measures the fraction of relevant materials that are actually retrieved. So the analyst responsible for developing a comprehensive assessment, is already working at a disadvantage. The objective was to automatically identify the topics of news stories. This very encouraging result suggests that automatic topic detection could become a fundamental enhancement to information retrieval and utilization 14. Substantial success has been achieved in this form of extraction of low-level semantics.