An efficient use of lexical cohesion is described for ranking text units according to their contribution in defining the meaning of a text (textual saliency), their ability to form a cohesive subtext (textual connectivity) and the extent and effectiveness to which they address the different topics which characterize the subject matter of the text (topic aptness). A specific application is also discussed where the method described is employed to build the indexing component of a summarization system to provide both generic and query-based indicative summaries.