The psychometric characteristics of the Test of Written English (TWE) rating scale were explored. Rasch model scalar analysis methodology was employed with more than 4,000 scored essays across 2 elicitation prompts to gather information about the rating scale and rating process. Results suggested that the intervals between TWE scale steps were surprisingly uniform and that the size of the intervals was appropriately larger than the error associated with assignment of individual ratings. The proportion of positively misfitting essays was small (approximately 1% of all essays analyzed) and was approximately equal to the proportion of essays that required adjudication by a third reader. This latter finding, along with the low proportion of misfitting readers detected, provided preliminary evidence of the feasibility of employing Rasch rating scale analysis methodology for the equating of TWE essays prepared across prompts. Some information on characteristics of misfitting readers was presented that could be useful in the reader training process. Appendixes present the TWE Scoring Guide and the mathematical specification of the rating model. (Contains 9 tables and 26 references.) (Author/SLD)