The Maui Hawaii Educational consortium (the Maui School District and Maui Community College) sought scientifically based evidence for the effectiveness of the "Cognitive Tutor (CT) Algebra I Curriculum" to inform adoption decisions. Decision makers were particularly interested in whether the use of the "CT" program affects achievement of their students and is a useful tool for teachers. The participating teachers used the program in their randomly selected "CT" classes for six months during the 2005-2006 school year while teaching their other classes with their standard materials. The experiment involved nine teachers, 22 classes, and 541 students. The experiment for the most part was unable to detect any impact of "Cognitive Tutor" on student achievement. Of the four sub-strands, the analysis found negative results for two of them: Quadratic Equations and Algebraic Operations. The results must be interpreted in the context of the particular resources for the implementation of the program on Maui, which were not favorable. While teachers gave a generally positive view of "CT", they reported difficulties with implementation--particularly access to computers. The researchers conducted an additional exploratory analysis of the data provided by the "CT" intervention on units completed. This indicated that there is an overall positive relationship between the number of units completed and student outcomes on the Northwest Evaluation Association (NWEA) test. (Contains 11 figures, 21 tables, and 3 footnotes.) [For research summary, see ED539000.]