Many tests used in educational settings to identify learning difficulties endeavour to pick up only the lowest performers. Yet these tests are generally developed within a Classical Test Theory (CTT) paradigm that assumes that data do not have significant skew. Rasch analysis is more tolerant of skew and was used to validate two newly developed tests of phonological and orthographic processing. These tests were administered to 172 Victorian Grade 3 students so that preliminary chronological norms could be generated. Despite a level of skew that would cause difficulties in a CTT paradigm, the tests were found to be acceptable as per Rasch analysis and, as such, provide additional and important information on poor-performing students. Preliminary norms for the test are provided.