Recent papers of document examiners have included dicussions of findings stated in terms of probability, and have raised questions about the propriety of giving such testimony in criminal trials. This study asserts that formation of a conclusion is progressive, that examination may be terminated in some cases with a statement of probability, and that examiners must report whatever conclusion they reach and must describe the evidence that brought about that conclusion. If, as a result of laboratory work, document examiners are asked by a competent authority to appear in court, they have an obligation to take the witness stand and respond to questions of attorneys and the court. The conclusion of probability or warranted assertion, once made formal by incorporation into a written report or delivered orally as a part of a laboratory procedure, should become available as testimony upon request by competent authority. Ten references are included. (Author abstract modified)