The most common problem with the introduction to a research article is lack of focus. A research article in not a review article, and it is not necessary, or prudent, to provide a review of the topic or of the anatomy and physiology of any pertinent organ system. The readers of CHEST, for example, are probably well versed in the organs of the thoracic cavity. Another common problem is overuse of references. Again, a review article most likely would have a wider and deeper reference list. For an article reporting the results of a hypothesis-testing clinical trial, it is important to credit the work of others, but it is inappropriate to cite every reference on the topic. Use the most recent, most direct, most succinct, and the most relevant references (the term elegant is often applied to these references). Use of too many references in a hypothesis-testing article suggests that the author is not truly knowledgeable in the field and cannot discern the most important studies on the topic. On the other side of the coin, failure to cite the work of others in the area is inexcusable.