The questioned document examiner studies letter design and size on two or more documents. After studying the markings, the questioned document expert ventures an opinion about whether the same person authored the two documents. The hard data the expert uses take the form of specimens or exemplars of the suspected author's handwriting style. Due to a writer's wide range of variation, it is necessary to examine a large volume of specimen writing when comparing a suspected writing. Contemporary specimens are preferred. The key to the examination is finding a sufficiently large number of individualistic writing characteristics to permit a positive opinion of identity. To date, experts in the questioned document field have been unable to formulate mathematical interpretive standards for deciding whether there is a match. The number of significant and consistent characteristics which must be present in two writings before a conclusion of identity can be expressed can be taught only by experience. Generally, this determination depends on the degree of significance accorded each individual characteristic, and there are no quantifiable criteria which dictate how much significance a particular writing characteristic is given. The American Board of Forensic Document Examiners has mounted recent efforts to upgrade the training of examiners. These efforts, combined with the research underway to refine interpretive standards should help in making document examination a more exact and scientific discipline. In court, the document examiner should present his/her conclusions and reasons for them and must be prepared to illustrate them through photographs. (editor summary modified)