[The writing of scientific articles].

The American writer Ernest Hemingway, 1898--1961, said the following about the art of writing: ‘‘We are all apprentices in a craft where no one ever becomes a master’’. This phrase also applies to writers of scientific texts. We are apprentices and self-taught writers in this difficult task of producing quality scientific writing. Creating a good text is the result of the hard work of writing. This is the opinion of experienced writers that consider other influences, such as inspiration, as being less important. Mark Twain, 1835--1910, also an American writer, proclaimed that conviction by promoting his three rules for writing well: ‘‘the first is to review; the second is to review and the third is to review’’. What does the editor of a scientific journal expect from a manuscript submitted for publication? Firstly, that it originates from methodologically correct research, performed on a relevant and appropriate theme for the journal. He will be even more pleased if the text is in agreement with the learned rules of the language in which it was written and if it contains characteristics that demonstrate its high -quality production. Among these characteristics are clarity, for the reader to understand what he reads; brevity, not to waste the reader’s time and space in the journal; accuracy, not to cheat or embarrass the reader; elegance, to attract and keep the reader’s attention and even delight him; and the logical sequence in the presentation of facts and arguments, to ensure continuity of reading.1 The presentation of the results sequence of an investigation is currently standardized in the major scientific journals in the health area. Four sections constitute the original scientific paper: introduction, methods, results, and discussion. This structure, called IMRD or IMReD, originated in the 1940s and was gradually adopted, being the only format used from the 1980s onwards.2