KIPP is a network of charter schools designed to transform and improve the educational opportunities available to low-income families, and ultimately, prepare students to enroll and succeed in college. KIPP’s rapidly expanding network includes more than 140 schools in 20 states and Washington, DC, including 74 middle schools as of the 2013-2014 school year.

KIPP Middle School Study

Mathematica conducted a rigorous multi-year evaluation of KIPP focusing on the following questions:

• What are the impacts of KIPP middle schools on student achievement and other outcomes, and how do these outcomes compare with those of students at other schools?
• Does the performance of KIPP students—both within and beyond core academic areas—suggest that they are on a path toward college attainment and persistence?

Mathematica used both a lottery-based design and a quasi-experimental, matched comparison group design to evaluate student outcomes over a broad range of KIPP middle schools. The matched comparison group design was used to examine the effects of attending a KIPP middle school on student achievement in math, reading, science, and social studies, based on a sample of 41 KIPP schools. The lottery-based design was used in a subset of 13 of these KIPP middle schools to estimate the effects of being admitted to a KIPP school on student achievement and other student outcomes.

Key findings from the KIPP middle school study include:

• KIPP middle schools have positive and statistically significant impacts on student achievement across all years and all subject areas examined.
• The magnitude of KIPP’s achievement impacts is substantial.
• The matched comparison group design produced estimates of KIPP’s achievement impacts similar to estimates of the same impacts based on an experimental, lottery-based design.
• In the lottery sample, average KIPP impacts on a nationally normed, low-stakes test that includes items assessing higher-order thinking skills were similar to impacts on high-stakes state tests.

KIPP i3 Scale-Up Grant Evaluation

As part of KIPP’s $50 million Investing in Innovation (i3) grant awarded in 2010 by the U.S. Department of Education, Mathematica built on this initial study via a rigorous evaluation of KIPP as it “scales up.” The five-year project, designed to address the question of whether KIPP can maintain its effectiveness as the network grows, had three primary components:

• An impact analysis, using lottery-based and quasi-experimental design methods similar to those employed in the first study, will estimate the effect of KIPP schools on student achievement, attainment, and other outcomes at the elementary, middle, and high school levels.
• An implementation analysis describing, in depth, KIPP’s leadership development programs at the local and national levels.
• A correlational analysis, investigating factors related to impacts, examining specific characteristics that may distinguish higher-performing from lower-performing schools within the network.

Pre-Kindergarten Impacts Over Time: An Analysis of KIPP Charter Schools

Building on our 2015 report showing that KIPP elementary schools had positive impacts on students’ reading and math skills after three years, Mathematica conducted a study for the Laura and John Arnold Foundation to estimate the impact of KIPP pre-K programs and to explore whether any impacts persist as students advance beyond kindergarten.

Mathematica’s research team followed students who entered randomized lotteries for KIPP pre-K programs and examined their performance five years later, when the students were typically in second grade. To isolate the additional benefit of KIPP pre-K, the researchers compared these impacts to those of KIPP elementary schools that did not offer pre-K. The study concluded that together, KIPP pre-K and early elementary grades have a positive impact on students’ reading and mathematics skills and that KIPP pre-K appears to offer an additional benefit beyond the impact of KIPP elementary school. The study also found that KIPP pre-K and early elementary grades may improve some of students’ executive function skills, including their working memory and ability to follow instructions.

The report identifies key features of the KIPP pre-K programs in the study sample, based on interviews with KIPP staff at study schools. These features may provide helpful context about what could be driving the differences in impacts between KIPP pre-K and non-KIPP programs.