Conclusions from an examination of the results of the National Assessment of Educational Progress indicate that it furnishes little help for those involved in the publication of composition textbooks. Four main difficulties in making inferences from the Assessment data on writing are (1) it is not clear why individuals perform as well or as poorly as they do; (2) it is not known whether examinations measure writing competency, rather than something else (e.g., maturity or psychological development); (3) it is impossible to determine whether individuals tell the truth about how often they write or about what kinds of writing they do, and (4) the objectives for writing are too narrow and do not indicate current thinking about the importance in the schools of personal and creative writing. Nonetheless, the findings can be useful to linguists, can provide a base against which further assessments of writing can be compared and suggest the need for a number of carefully controlled studies about how persons develop competency in various kinds of writing. (DD) Aspect of National Assessment (NAEP) dealt with in this document: Results (Interpretation).