Abstract, conclusions and summaries

MOST scientific and engineering papers are preceded by an Abstract, and end with a Conclusions or Summary or both. The functions of these parts of a document are vaguely understood by most readers and even writers. Yet only too often they are treated as if they were cloaks, worn alternately by different bodies on different occasions. For example, a recent text [I] on technical writing treats Abstract and Summary as practically interchangeable. Again, Summary and Conclusions frequently appear as a single unit at the end of articles. The purpose of this note is to illustrate that provided the paper is extensive enough to justify inclusion of all three sections, they can all have different identities.