As part of a project on assessing deep understanding of subject matter, a study was conducted to assess students' knowledge of history by focusing on essay writing. Reading a provided text was incorporated into the assessment procedure. Ratings from five high school history teachers were compared with those of four English teachers for 85 essays from 11th-grade advanced placement students in a suburban high school. No significant differences in student performance were found for the two text passages or question type (brief or extended) in ratings of either group. English and history teachers were looking at student papers in fundamentally similar ways, but scoring criteria were not adequate in that they focused on what teachers said they valued, rather than what they actually would write themselves. Using an expert-novice model, new questions were developed, and the new test was administered to 250 11th graders and scored under new scoring rubrics. Higher interrater reliabilities encouraged researchers to train four history teachers in the new scoring approach. Ongoing research is examining the utility of the new scoring focus for high school students in two school districts. The study illustrates the complexity of developing new and useful assessments. Eight tables summarize test development principles, and a 30-item list of references is included. (SLD)