Standardized testing, usually in the form of a multiple choice test, has dominated educational reform throughout Mississippi for the past 2 decades. Because of the minimal impact that standardized testing has traditionally had on curriculum decisions and classroom instruction, a paradigm shift in assessment format was adopted in the State from a narrow, criterion-referenced minimum competence to a broader, performance-based model. This pilot study examined teachers' perceptions of this new Mississippi Assessment System (MAS) and its extent as well as its impact on teacher judgment, modifications to classroom instruction, and non-traditional as well as traditional assessment formats. A 2-part questionnaire and teacher interviews were developed to collect both demographic and teachers' perceptions data. Participants were K-12 teachers (N=220) located in 2 small school districts in southern Mississippi. Data were analyzed using canonical correlation procedures. Results suggested that 10 demographic contributors influenced teachers' judgments, instructional change, and assessment/program evaluation. Quantitative and qualitative findings indicated that overall teacher perceptions, based on professional judgment, supported the changes in the MAS that combined traditional and non-traditional testing formats and that assessment results could help them select appropriate teaching strategies, curriculum, and educational programs. Participants also expressed a need for change in their classroom instruction to better prepare children for the new, non-traditional formats. (Contains 12 references.) (NAV)