This study describes the Math and Science Partnership Program Evaluation (MSP-PE) during the project's first two years and provides the evaluation framework being used to assess the National Science Foundation's MSP Program. The study conveys the MSP-PE's ongoing design and implementation. To show how they reflect the nature of the MSP Program, the study addresses the following questions: (a) What are the MSP Program's main themes? (b) What kinds of activities have the program's awardees been putting into place? (c) What are the awardees doing to assess K-12 student achievement outcomes? and given the preceding conditions, (d) What is the framework and design for the MSP-PE? The study shows how the framework and the emerging evaluation derive from the program's main themes and its early activities, also giving readers a glimpse of the program's activities. The study traces the rationale behind a multi-institutional framework that covers a series of pathways in the K-20 span of mathematics and science education. This systems approach calls for a series of substudies that collectively address the multifaceted interorganizational and intraorganizational relationships in the MSP Program. The evaluation's framework provides a unifying scope for the series of substudies--all of which have been undertaken as part of the MSP-PE. Some of MSP-PE's early substudies are contained in this special issue. (Contains 6 tables, 3 figures and 7 footnotes.)