Tests of statistical significance often play a decisive role in establishing the empirical warrant of evidence-based research in education. The results from pattern-based assessment items, as introduced in this paper, are categorical and multimodal and do not immediately support the use of measures of central tendency as typically related to interpretations of measures of statistical significance. Responses from the duplicate implementation of selected pattern-based items (PBIs) in successive grades (3-8) as part of the statewide Interim Assessment Program in Texas are used to illustrate how non-parametric methods can be used to establish statistically significant comparisons of student results. Not all the repeat-item results improved across years. [For the complete proceedings, see ED657822.]