This thesis examines the Supplemental Educational Services (SES) component of the No Child Left Behind Act of 2001 (NCLB) and focuses on the effect of this program improvement intervention on the academic performance of low-achieving students who participate compared to the academic performance of low-achieving students who are eligible but do not participate in the program. Public schools and districts that serve a high percentage of students from low-income families receive federal funding under Title I of the Elementary and Secondary Education Act of 1965, reauthorized in 2001 as the No Child Left Behind Act (NCLB). Under NCLB, schools that receive Title I funds are required to test students annually to assess proficiency of basic skills in English-language arts and mathematics. Schools must demonstrate Adequate Yearly Progress (AYP) by increasing the margin of students who are academically proficient each year. Schools that fail to achieve the margin of proficiency after two years must reserve 15 percent of the Title I grant to provide Supplemental Educational Services (SES) for low-achieving, low-income students. The SES program is tutoring offered to students before- or after-school by private organizations not affiliated with the public school or district. Approved SES providers receive payment for the tutoring services from the district's Title I funds that are reserved pursuant to the program improvement sanction. NCLB requires the states to approve and authorize tutoring organizations or individuals to provide the SES program, and California requires firms to apply annually to be authorized and to submit accountability reports annually to maintain eligibility as a provider. In addition to information regarding providers' business operations and credential qualifications, SES providers must provide descriptive information regarding the tutoring services it delivers to individual students. However, the state or districts do not systematically evaluate SES providers to determine the statistical effect of the tutoring on students' academic achievement. Whereas NCLB is a standards-based education reform policy, the absence of research-based evidence of the SES program effect creates ambiguity regarding the intent of the intervention strategy and provokes questions as to whether the policy meets the test of Pareto improvement. This thesis uses a linear regression analysis and administrator interviews to evaluate the estimated effect of SES participation on the academic achievement of students attending two program improvement schools in a small suburban school district located in Northern California. The regression results indicate that a student's SES participation did not have a statistically significant effect on the student's test score for either English-language arts or mathematics. The conclusions drawn from the interviews with school district administrators indicate that school officials are uncertain and doubtful about the effectiveness of the SES intervention for improving student's academic performance on standardized test scores, particularly in comparison to program improvement strategies implemented in the classroom. With regard to implementation of the SES program, the interviews revealed that the district office assumes the role of ensuring compliance with the NCLB mandates and the delivery of the SES program. The district conforms to the administrative recommendations and requirements of the state for managing the program but does not engage in additional monitoring or statistical evaluation of the effectiveness of the SES program or providers. School officials are generally satisfied with the way in which the district administers the SES program, yet they are hesitant to endorse the program as an effective use of resources in the absence of research-based evidence. Although the district does not conduct any formal survey to assess the level of satisfaction with the SES program among participants, the administrators report that informal communications with parents and students reveal generally positive opinions about the program. I recommend a systematic approach for auditing the performance of the independent SES providers for evidence that the tutoring programs are effectively improving academic proficiency among the students who are eligible and participate in the entitlement program.