This book explores the factors affecting choice of noun phrase in texts from the perspective of the referring expression and identity chain. To do this, the author focuses on the concepts of text, discourse, reference, coreference, and anaphora, elaborating a new system of classification for noun phrases based on the kind of reference that they entail. What factors make a given expression more effective as a means of designating a given referent depends in general on relevance and, especially, on what is mutually manifest. Through analysis of a corpus, it is shown that each kind of referring expression is appropriate to different contexts with none taking precedence over the others. It is also found that, together with the information structure of the clause seen as a representation and the syntactic structure by which this is encoded, four factors affect noun phrase selection: referential efficacy, the principle of economy, the informative function and the avoidance of formal repetition. Most research into cohesion has focussed on English; a study of Italian is also an opportunity to broaden research horizons.