Data presented in this report are the results of the special assessment of writing mechanics conducted during the 1978-79 school year by the Education Commission of the States (ECS) for the Department of Defense Dependents Schools (DoDDS). The purposes of the study were (1) to examine writing abilities of 9-, 13-, and 17-year-old students enrolled in the DoDDS system, and (2) to compare their writing abilities with those of students enrolled in schools within the continental United States. Once a representative sample of students at each of the three ages was selected, assessment materials were distributed. These materials included an instruction manual for DoDDS personnel, administering the assessment, the assessment booklets, and a paced audiotape presenting the materials to students. Each assessment booklet contained an essay writing task. Following assessment, the materials went on to the regional coordinator, and then to the scoring site. This report is organized by age group; a profile of the "average" essay is presented and discussed; a brief examination of the range of essays is provided; and a comparison of "average" papers by DoDDS students with those of their national counterparts is discussed. (Author/GK) Primary type of information provided by report: Procedures (Field Administration); Results (Special Analyses).