IN this issue we publish a revised "Information for Authors" page, including three changes that should interest readers as well as authors.First, we are adopting a new, structured format for abstracts. Journal abstracts will henceforth consist of four paragraphs labeled Background, Methods, Results, and Conclusions. Sometimes, when appropriate, two of the first three paragraphs will be combined in one. The object is to enable readers to grasp the essence of an article quickly by providing a framework that will present the work in a logical, complete, yet concise fashion. For many years we have been advising authors to organize . . .