This study examined the relationship between high-stakes testing pressure and student achievement across 25 states. Standardized portfolios were created for each study state. Each portfolio contained a range of documents that told the "story" of accountability implementation and impact in that state. Using the "law of comparative judgments," over 300 graduate-level education students reviewed one pair of portfolios and made independent evaluations as to which of the two states' portfolios reflected a greater degree of accountability pressure. Participants' judgments yielded a matrix that was converted into a single rating system that arranged all 25 states on a continuum of accountability "pressure" from high to low. Using this accountability pressure rating we conducted a series of regression and correlation analyses. We found no relationship between earlier pressure and later cohort achievement for math at the fourth- and eighth-grade levels on the National Assessment of Educational Progress tests. Further, no relationship was found between testing pressure and reading achievement on the National Assessment of Education Progress tests at any grade level or for any ethnic student subgroup. Data do suggest, however, that a case could be made for a causal relationship between high-stakes testing pressure and subsequent achievement on the national assessment tests--but only for fourth grade, non-cohort achievement and for some ethnic subgroups. Implications and directions for future studies are discussed. [Appended to this document are: (1) Appendix A: Examples of Context for Assessing State-Level Stakes Sheet; (2) Appendix B: Two Examples of Completed Rewards and Sanctions Worksheet Texas and Kentucky; (3) Appendix C: Method for the Inclusion of Media in Portfolios; (4) Appendix D: Summary News Search: Massachusetts; (5) Appendix E: Summary of News Searches in Five Pilot States; and (6) Appendix F: Summary of New Search Rationale--Finalized System.] (Contains 56 tables and 258 footnotes.)