As part of the mandate of the Alberta Government's Student Evaluation Branch to monitor changes in student achievement, the Humanities Diploma Examinations Unit compared the written work from 1984 and the 1990 English 30, Social Studies 30, and English 33 Canadian provincial diploma examinations. Full-length essays written by over 30,000 students in 1984 and a similar number in 1990 were scored according to a criterion-referenced scoring guide that described features of writing performance in 5-point scales covering several dimensions: thought and detail, organization, style, and correctness of language. Comparisons were made using two standards: "satisfactory," which represented work at an acceptable level for graduating students; and "excellent," which represented outstanding work for graduating students. Results indicated that: (1) papers judged to be satisfactory were significantly better in all three subjects in 1990 than in 1984; (2) improvements were noted as well in the papers scored "excellent"; (3) changes were particularly dramatic in the English 30 1990 essays; and (4) the descriptions of students' written work in all three subjects revealed common features of writing at the mid and top levels of performance. Results document an increase in standards (particularly at the "satisfactory" level) as well as improvements in actual student performance. (Six tables presenting key features of student essays are included; an appendix of data and the written-response assignments for 1984 and 1990 are attached.) (RS)