It is the author's contention that characteristics of handwriting comparisons often thwart one's ability to form specific conclusions for the following reasons: (1) Handwriting comparisons usually consist of open sets rather than closed sets. In closed sets, it is known that a match exists and the only requirement is to select the proper one. In open sets, it is not known if a match exists and a more stringent standard of accountability is required. (2) The quality and quantity of the evidence may be inadequate. (3) The process of elimination of possible writers frequently is not amenable to definitive conclusions. The lack of similarity between the questioned and known samples is not a sufficient basis for concluding that they came from different sources. 3 figures and 5 references. (Author abstract)