Clustering by directions algorithm to narrow search queries

This article describes a novel algorithm called clustering by directions. This algorithm is designed to create a list of words which serve as suggestions for users of search engines how to modify their current search query. The algorithm focuses on preparing various suggestions. It concerns modifying queries by adding more words to them. A list of suggested words is presented to the user in a form of a tag cloud. Experiments which were performed with the algorithm show its usefulness.