How teachers' judgments about student literacy behavior were analyzed under the Rasch model is described. The analysis was done to assist staff of the Western Australian Department of Education to revise aspects of a literacy program called "First Steps" for the early years of school. First Steps uses a developmental continuum of small phases of student development. To illustrate the analysis, the Spelling Development Continuum is used. Data for the validation of this continuum were provided by 39 teachers of years 1, 3, 5, and 7, with reevaluation data from an additional 88 teachers. Data consisted of judgments about the extent to which up to 10 students in each class exhibited evidence of behavior described by continuum indicators. Data were analyzed with the computer program Quest, which produces item- response-theory calibrations of indicators. The application of Rasch modeling techniques made it possible to extend the concern of the research beyond the order of the indicators to a more complex examination of the entire continuum, and this resulted in rewording of some indicators and more general investigations of the whole continuum. Nine exhibits demonstrate the analysis steps. (Contains 6 references.) (SLD)