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Elements of preschool correlated with outcomes in early elementary grades — May 2017


What does the research say about which elements of the preschool experience are correlated with student outcomes in grades K–3?


Following an established REL West research protocol, we conducted a search for research reports as well as descriptive study articles on the elements of preschool experiences that are correlated with student outcomes in the early grades. The sources included ERIC and other federally funded databases and organizations, research institutions, academic research databases, and general Internet search engines. (For details, please see the methods section at the end of this memo.)

We have not evaluated the quality of references and the resources provided in this response. We offer them only for your reference. Also, we searched for references through the most commonly used sources of research, but the list is not comprehensive and other relevant references and resources may exist.

Research References

Ansari, A., & Winsler, A. (2014). Montessori public school pre-K programs and the school readiness of low-income Black and Latino children. Journal of Educational Psychology, 106(4), 1066–1079. Retrieved from

From the abstract: “Within the United States, there are a variety of early education models and curricula aimed at promoting young children’s pre-academic, social, and behavioral skills. This study, using data from the Miami School Readiness Project (Winsler et al., 2008, 2012), examined the school readiness gains of low-income Latino (n = 7,045) and Black (n = 6,700) children enrolled in 2 different types of Title-1 public school pre-K programs: those in programs using the Montessori curriculum and those in more conventional programs using the High/Scope curriculum with a literacy supplement. Parents and teachers reported on children’s socio-emotional and behavioral skills with the Devereux Early Childhood Assessment (Lebuffe & Naglieri, 1999), whereas children’s pre-academic skills (cognitive, motor, and language) were assessed directly with the Learning Accomplishment Profile–Diagnostic (Nehring, Nehring, Bruni, & Randolph, 1992) at the beginning and end of their 4-year-old pre-K year. All children, regardless of curriculum, demonstrated gains across pre-academic, socio-emotional, and behavioral skills throughout the pre-K year; however, all children did not benefit equally from Montessori programs. Latino children in Montessori programs began the year at most risk in pre-academic and behavioral skills, yet exhibited the greatest gains across these domains and ended the year scoring above national averages. Conversely, Black children exhibited healthy gains in Montessori, but they demonstrated slightly greater gains when attending more conventional pre-K programs. Findings have implications for tailoring early childhood education programs for Latino and Black children from low-income communities.”

Barnett, W. S., Jung, K., Youn, M-J., & Frede, E. C. (2013). Abbott preschool program longitudinal effects study: Fifth grade follow-up. New Brunswick, NJ: National Institute for Early Education Research (NIEER), a unit of Rutgers, The State University of New Jersey. Retrieved from

From the abstract: “New Jersey’s Abbott Preschool program is of broad national and international interest because the Abbott program provides a model for building a high-quality system of universal pre-K through public-private partnerships that transform the existing system. The program offers high-quality pre-K to all children in 31 New Jersey communities with high levels of poverty and about a quarter of the state’s children. The Abbott Preschool Program Longitudinal Effects Study (APPLES) assesses the impact of this pre-K program on children’s learning and development based on a cohort of children who completed their 4-year-old year in 2004–05. APPLES previously estimated the impacts of Abbott pre-K at kindergarten entry and second grade follow-up. The 4th and 5th grade APPLES follow-up finds that Abbott preschool programs increased achievement in Language Arts and Literacy, Math, and Science. The authors’ estimates indicate that two-years of pre-K beginning at age 3 had larger persistent effects on achievement than did one year of pre-K.”

Bierman, K. L., Nix, R. L., Heinrichs, B. S., Domitrovich, C. E., Gest, S. D., Welsh, J. A., & Gill, S. (2014). Effects of Head Start REDI on children’s outcomes one year later in different kindergarten contexts. Child Development, 85, 140–159. Retrieved from

From the abstract: “One year after participating in the Research-based, Developmentally Informed (REDI) intervention or ‘usual practice’ Head Start, the learning and behavioral outcomes of 356 children (17% Hispanic, 25% African American; 54% girls; Mage = 4.59 years at initial assessment) were assessed. In addition, their 202 kindergarten classrooms were evaluated on quality of teacher–student interactions, emphasis on reading instruction, and school-level student achievement. Hierarchical linear analyses revealed that the REDI intervention promoted kindergarten phonemic decoding skills, learning engagement, and competent social problem-solving skills, and reduced aggressive–disruptive behavior. Intervention effects on social competence and inattention were moderated by kindergarten context, with effects strongest when children entered schools with low student achievement. Implications are discussed for developmental models of school readiness and early educational programs.”

Camilli, G., Vargas, S., Ryan, S., & Barnett, W. S. (2010). Meta-analysis of the effects of early education interventions on cognitive and social development. Teachers College Record, 112(3), 579–620. Retrieved from

From the abstract: “Following over 50 years of research, this meta-analysis of 123 key studies on preschool programs found significant benefits from preschool participation. Most substantially, preschool attendance positively impacts the cognitive development of children. Additionally, the researchers found that preschool provides positive long-term outcomes on program participants’ social skills and school progress, including lower instances of grade-level retention and special education. Programs that include teacher-directed instruction and small groups were found to intensify these gains in early development. Additional intervention services administered before kindergarten also were found to promote program participants’ social skills and school progress, however these services negatively correlated with cognitive gains. The meta-analysis found that participants who used these extra services typically received less direct instruction, suggesting that the delivery of these additional services often detracts from the instructional hours of the preschool day.”

Cryer, D. (1999). Defining and assessing early childhood program quality. The ANNALS of the American Academy of Political and Social Science, 563(1). Retrieved from

From the abstract: “In the United States, there is a definition of quality of early care and education (ECE) programs that is widely accepted in the early childhood profession. It emphasizes a child-centered approach to raising children, with caring adults who are kind and gentle rather than restrictive and harsh and who protect children’s health and safety, while providing a wealth of experiences that lead to learning through play. According to the definition, individuality and creativity are encouraged rather than conformity. This definition is often criticized by those with differing perspectives, but in general, it appears to be valid for those who value the aspects of development that are associated with success in the current mainstream American educational system and society. In this article, the content, rationale, and criticisms of that definition of quality are presented. Methods used in its assessment, and information regarding its validity, are explained.”

Diamond, K. E., Justice, L. M., Siegler, R. S., & Snyder, P. A. (2013). Synthesis of IES research on early intervention and early childhood education (NCSER 2013-3001). Washington, DC: National Center for Special Education Research, Institute of Education Sciences, U.S. Department of Education. Retrieved from

From the report description: “The report describes what has been learned from research grants on early intervention and early childhood education funded by the Institute’s National Center for Education Research and National Center for Special Education Research, and published in peer-reviewed outlets through June 2010. This synthesis describes contributions to the knowledge base produced by IES-funded research across four focal areas:

  • Early childhood classroom environments and general instructional practices;
  • Educational practices designed to impact children’s academic and social outcomes;
  • Measuring young children’s skills and learning; and
  • Professional development for early educators.

Research supported by IES has made significant contributions to the evidence base in these areas. The authors also raise important questions for education research in the future, including:

  • What are the crucial features of high-quality early childhood education?
  • Which instruction is most effective for which children and under what circumstances?
  • How do we effectively and efficiently support teachers in improving their instruction?”

Graue, E., Clements, M. A., Reynolds, A. J., & Niles, M. D. (2004). More than teacher directed or child initiated: Preschool curriculum type, parent involvement, and children’s outcomes in the Child-Parent Centers. Education Policy Analysis Archives, 12(72), 1–38. Retrieved from

From the abstract: “This study investigated the contributions of curriculum approach and parent involvement to the short- and long-term effects of preschool participation in the Title I Chicago Child-Parent Centers. Data came from the complete cohort of 989 low-income children (93% African American) in the Chicago Longitudinal Study, who attended preschool in the 20 Child-Parent Centers in 1983–1985 and kindergarten in 1985–1986. We found that implementation of an instructional approach rated high by Head Teachers in teacher-directed and child-initiated activities was most consistently associated with children’s outcomes, including school readiness at kindergarten entry, reading achievement in third and eighth grades, and avoidance of grade retention. Parent involvement in school activities, as rated by teachers and by parents, was independently associated with child outcomes from school readiness at kindergarten entry to eighth grade reading achievement and grade retention above and beyond the influence of curriculum approach. Findings indicate that instructional approaches that blend a teacher-directed focus with child-initiated activities and parental school involvement are origins of the long-term effects of participation in the Child-Parent Centers.”

Marcon, R. A. (2002). Moving up the grades: Relationship between preschool model and later school success. Early Childhood Research & Practice, 4(1). Retrieved from

From the abstract: “A follow-up study of children who began school at age 4 was conducted to examine the influence of three different preschool models (child-initiated, academically-directed, or a ‘combination’ approach) on later school success. These children from an urban school district were studied again in Year 5 as they prepared to leave the primary grades and in Year 6 when they were scheduled to enter fourth grade if not previously retained. The study examined report card grades, retention rates, and special education placement of 160 children at the end of their fifth year in school and 183 children at the end of their sixth year in school. The sample was 96 percent African American; 54 percent of the sample was female. Seventy-five percent of the children qualified for subsidized school lunch, and 73 percent were living in single-parent families. Academically, girls surpassed boys at the end of Year 5, and this difference persisted into the next grade level. Children whose preschool experience was more academically directed had been retained less often than their peers. No differences attributable to preschool model were found for special education placement. By the end of children’s fifth year in school, there were no differences in academic performance of children who had experienced the three different preschool models. By the end of their sixth year in school, children whose preschool experiences had been academically directed earned significantly lower grades compared to children who had attended child-initiated preschool classes. Children’s later school success appears to have been enhanced by more active, child-initiated early learning experiences. Their progress may have been slowed by overly academic preschool experiences that introduced formalized learning experiences too early for most children’s developmental status.”

Morris, P. A., Mattera, S. K., & Maier, M. F. (2016). Making pre-K count: Improving math instruction in New York City. New York, NY: MDRC. Retrieved from

From the abstract: “In the context of a persistent achievement lag among low-income children despite substantial investments in early education, policymakers and practitioners continue to seek ways to improve the quality of children’s preschool experiences. The Making Pre-K Count study addresses whether strengthening prekindergarten (pre-K) instruction in math, hypothesized to be a ‘linchpin’ skill in children’s development, can improve children’s short- and longer-term learning. Specifically, the study rigorously evaluated the effect of an evidence-based math curriculum called Building Blocks along with ongoing training and in-classroom coaching, relative to the typical pre-K experience. Making Pre-K Count took place in 69 pre-K sites and over 170 classrooms across New York City. Thirty-five of the pre-K sites were assigned to receive the math curriculum, training, and coaching over two years (the ‘BB-MPC’ group), while the other 34 were assigned to continue their typical programming (as the ‘pre-K-as-usual’ group). Outcomes for children were assessed in the second year of the study, after teachers were familiar with the program. Over the course of the study, the typical pre-K experience in New York City was changing rapidly, with a new focus on the Common Core math standards and a major expansion into universal pre-K.”

Peisner-Feinberg, E. S., Schaaf, J. M., Hildebrandt, L. M., Pan, Y., & Warnaar, B. L. (2015). Children’s Kindergarten outcomes and program quality in the North Carolina pre-Kindergarten program: 2013-2014 statewide evaluation. Chapel Hill, NC: The University of North Carolina’s FPG Child Development Institute. Retrieved from

From the abstract: “The 2013–2014 North Carolina Pre-Kindergarten (NC Pre-K) Evaluation study was designed to examine the longitudinal outcomes through kindergarten for children who attended the Pre-K program, along with comparisons to previous cohorts of program attendees. A sample of 561 children was included in the study, with data gathered at the beginning and end of NC Pre-K (2012–2013) and kindergarten (2013–2014) to examine their growth in skills. Researchers conducted individual assessments of children’s language, literacy, math, and general knowledge skills and gathered teacher ratings of behavior skills. For 119 Spanish-speaking dual language learners (DLLs) in the sample, parallel assessments were conducted in both English and Spanish to examine their progress when measured in both languages. In addition, program characteristics and services were examined for the 2013–2014 NC Pre-K Program using data from the statewide databases, as well any changes over time since the program became statewide in 2003–2004. Information about the observed quality of classroom practices was obtained from NC rated license assessments of a sample of 374 NC Pre-K classrooms conducted by the NC Rated License Assessment Project (NCRLAP) in 2013–2014.”

Phillips, D., Gormley, B., & Anderson, S. (2016). The effects of Tulsa’s CAP Head Start program on middle-school academic outcomes and progress. Developmental Psychology, 52(8), 1247–1261. Retrieved from

From the abstract: “This study presents evidence pertinent to current debates about the lasting impacts of early childhood educational interventions and, specifically, Head Start. A group of students who were first studied to examine the immediate impacts of the Tulsa, Oklahoma, Community Action Project (CAP) Head Start program were followed-up in middle school, primarily as 8th graders. Using ordinary least squares and logistic regressions with a rich set of controls and propensity score weighting models to account for differential selection into Head Start, we compared students who had attended the CAP Head Start program and enrolled in the Tulsa Public Schools (TPS) as kindergarteners with children who also attended TPS kindergarten but had attended neither CAP Head Start nor the TPS pre-K program as 4-year-olds. CAP Head Start produced significant positive effects on achievement test scores in math and on both grade retention and chronic absenteeism for middle-school students as a whole; positive effects for girls on grade retention and chronic absenteeism; for white students on math test scores; for Hispanic students on math test scores and chronic absenteeism, and for students eligible for free lunches on math test scores, grade retention, and chronic absenteeism. We conclude that the Tulsa CAP Head Start program produced significant and consequential effects into the middle school years.”

Preschool Curriculum Evaluation Research Consortium. (2008). Effects of preschool curriculum programs on school readiness (NCER 2008–2009). Washington, DC: National Center for Education Research, Institute of Education Sciences, U.S. Department of Education. Retrieved from

From the abstract: “In 2002, the Institute of Education Sciences (IES) began the Preschool Curriculum Evaluation Research (PCER) initiative to conduct rigorous efficacy evaluations of available preschool curricula. Twelve research teams implemented one or two curricula in preschool settings serving predominantly low-income children under an experimental design. For each team, preschools or classrooms were randomly assigned to the intervention curricula or control curricula and the children were followed from pre-kindergarten through kindergarten. IES contracted with RTI International (RTI) and Mathematica Policy Research (MPR) to evaluate the impact of each of the 14 curricula implemented using a common set of measures with the cohort of children beginning preschool in the summer-fall of 2003. This report provides the individual results for each curriculum from the evaluations by RTI and MPR. Chapter 1 describes the PCER initiative and details the common elements of the evaluations including the experimental design, implementation, analysis, results, and findings. Chapters 2–13, respectively, provide greater detail on the individual evaluations of the curricula implemented by each research team including information on the curricula, the demographics of the site-specific samples, assignment, fidelity of implementation, and results. Appendix A presents results from a secondary analysis of the data. Appendix B provides greater detail regarding the data analyses conducted. Appendixes C and D provide additional information regarding the outcome measures.” REL West note: Measures used are listed in Table 1.5 on page 11.

Weiland, C., & Yoshikawa, H. (2013). Impacts of a prekindergarten program on children’s mathematics, language, literacy, executive function, and emotional skills. Child Development, 84(6), 2112–2130. Retrieved from

From the abstract: “Publicly funded prekindergarten programs have achieved small-to-large impacts on children’s cognitive outcomes. The current study examined the impact of a prekindergarten program that implemented a coaching system and consistent literacy, language, and mathematics curricula on these and other nontargeted, essential components of school readiness, such as executive functioning. Participants included 2,018 four- and ?ve-year-old children. Findings indicated that the program had moderate-to-large impacts on children’s language, literacy, numeracy and mathematics skills, and small impacts on children’s executive functioning and a measure of emotion recognition. Some impacts were considerably larger for some subgroups. For urban public school districts, results inform important programmatic decisions. For policy makers, results con?rm that prekindergarten programs can improve educationally vital outcomes for children in meaningful, important ways.”

Williams, J. M., Landry, S. H., Anthony, J. L., Swank, P. R., & Crawford, A. D. (2012). An empirically-based statewide system for identifying quality pre-Kindergarten programs. Education Policy Analysis Archives, 20(7), 1–33. Retrieved from

From the abstract: “This study presents an empirically-based statewide system that links information about pre-kindergarten programs with children’s school readiness scores to certify pre-kindergarten classrooms as promoting school readiness. Over 8,000 children from 1,255 prekindergarten classrooms were followed longitudinally for one year. Pre-kindergarten quality indicators of intentional instruction, an early literacy focus, and professional development were key predictors of kindergarten outcomes. A latent profile analysis identified pre-kindergarten classrooms that were high on pre-kindergarten quality indicators and high on kindergarten outcomes (67.3%), low on pre-kindergarten quality and kindergarten outcomes (21.3%), or low on quality but high on outcomes (11.4%). The last group of classrooms was likely to serve middle-class children and not use the state program model. This project demonstrates how a scientific approach can inform stakeholders and parents about the effectiveness of early childhood programs.”

Other Resources

Ramani, G. B., & Brownell, C. A. (2014). Preschoolers’ cooperative problem solving: Integrating play and problem solving. Journal of Early Childhood Research, 12(1), 92–108. Retrieved from Full-text is available for purchase.

From the abstract: “Cooperative problem solving with peers plays a central role in promoting children’s cognitive and social development. This article reviews research on cooperative problem solving among preschool-age children in experimental settings and social play contexts. Studies suggest that cooperative interactions with peers in experimental settings are not as consistently beneficial to young children’s cognitive growth as they are for school-age children. In contrast, both theory and empirical research suggest that social play like that seen in early childhood classrooms is a context in which young children gain critical knowledge from peer cooperation. However, these contexts differ in how much they allow children to create and sustain their own joint goals, which likely influences their learning from cooperative interactions in experimental settings. Features of cooperative social play that allow preschool children to create joint goals are considered, and suggestions for future research are proposed to integrate these features into experimental settings in order to provide a fuller understanding of the development of cooperative problem solving in young children and its benefits.”

Southern Regional Education Board (SREB). (2015). Pre-K benefits: The facts on fade-out. Atlanta, GA: Author. Retrieved from

From the abstract: “As policymakers adopt policies for pre-K programs, they want to know that the programs are effective. Do the gains last? This brief report presents information that pre-k yields short-term academic gains; pre-k yields long-term academic gains; and pre-k yields substantial nonacademic benefits.”

Weisberg, D. S., Hirsh-Pasek, K., & Golinkoff, R. M. (2013). Guided play: where curricular goals meet a playful pedagogy. Mind, Brain, and Education, 7(2), 104–112. Retrieved from Full-text is available for purchase.

From the abstract: “Decades of research demonstrate that a strong curricular approach to preschool education is important for later developmental outcomes. Although these findings have often been used to support the implementation of educational programs based on direct instruction, we argue that ‘guided play’ approaches can be equally effective at delivering content and are more developmentally appropriate in their focus on child-centered exploration. Guided play lies midway between direct instruction and free play, presenting a learning goal, and scaffolding the environment while allowing children to maintain a large degree of control over their learning. The evidence suggests that such approaches often outperform direct-instruction approaches in encouraging a variety of positive academic outcomes. We argue that guided play approaches are effective because they create learning situations that encourage children to become active and engaged partners in the learning process.”

Zigler, E. F., & Bishop-Josef, S. J. (2009). Play under siege: A historical overview. Zero to Three, 30(1), 4–11. Retrieved from

From the abstract: “In this updated version of their chapter from ‘Children’s Play: The Roots of Reading’ (published by ZERO TO THREE in 2004), the authors describe the recent attack on play, in both early childhood and elementary education. They provide a historical overview of the contentious relationship between play and cognitive development. The authors stress the necessity of a whole child approach, including an appreciation for the essential role of play for cognitive, social, and physical development. Quality preschool education, they conclude, requires pursuing both hands-on, play-based learning and developmentally appropriate instruction of academic skills.”

Additional Organizations to Consult

National Institute for Early Education Research (

From the website: “The National Institute for Early Education Research (NIEER) conducts and communicates research to support high-quality, effective early childhood education for all young children. Such education enhances their physical, cognitive, and social development, and subsequent success in school and later life. The Institute offers independent, research-based advice and technical assistance to policymakers, journalists, researchers, and educators.”

WWC Evidence Review Protocol for Early Childhood Education Interventions, Version 3.0 (2014) (

From the IES website’s WWC abstract: “What Works Clearinghouse (WWC) reviews in this topic area focus on early childhood education (ECE) interventions designed for use in school- or center-based settings with 3- to 6-year-old children who are not yet in kindergarten and are attending a center-based program. The primary focus for early childhood education interventions is on cognitive, language, and behavioral competencies associated with school readiness (specifically, language, cognitive, and social-emotional development, print knowledge, phonological processing, early reading and writing, and math).

Systematic reviews of evidence in this topic area address the following questions:

  • Which ECE interventions improve preschool children’s school readiness (specifically, their language, cognitive, and social-emotional development, print knowledge, phonological processing, early reading and writing, and math)?
  • Does the effectiveness of ECE interventions differ by type of outcome?
  • Which ECE interventions are particularly effective for which children?”

NOTE: A link to the full protocol can be retrieved from IES web address listed above.

WWC Evidence Review Protocol for Early Childhood Education Interventions for Children with Disabilities, Version 2.0 (

From the IES website’s WWC abstract: “The What Works Clearinghouse (WWC) review in this topic area focuses on interventions that have a primary focus on outcomes associated with the school readiness of children with disabilities, including outcomes in the areas of cognition, communication competencies, literacy, mathematics achievement, social-emotional development and behavior, functional abilities,1 and motor development. The review focuses on early childhood education (ECE) interventions (curricula, practices, and therapies) designed for use with 3- to 5-year-old children who are not yet in kindergarten and older children who are attending a preschool program. These interventions must take place in a school or center-based preschool setting, or if they take place in other locations (such as clinical settings or family homes), they must be implemented under the direction of or in collaboration with a school, preschool, or program funded through the Individuals with Disabilities Education and Improvement Act (IDEA).

The review of evidence in this topic area addresses the following questions:

  • Which early childhood education interventions improve outcomes associated with school readiness among children with disabilities?
  • Does the effectiveness of early childhood education interventions for children with disabilities differ by type of outcome?
  • What types of early education interventions are particularly effective for which children with disabilities under which circumstances?

Individual intervention-level reports will be released on a periodic basis.

The review of individual studies underlies all What Works Clearinghouse (WWC) products, from reports on a single study to a systematic review of all studies on an intervention. The WWC’s Database of Study Findings provides data resulting from WWC reviews for every study that meets standards and is included in a quick review, single study review, or intervention report, as well as studies that have been reviewed for Department grant competitions.

The Database of Study Findings provides comprehensive data at the outcome level, a finer level of observation than any other WWC database. It includes 50 variables on more than 3,000 records, each representing an individual finding in a study. Finding-level variables include means, standard deviations, and sample sizes, for use in meta-analysis. Other new variables provide information on study populations (e.g., grade, race, ethnicity, English Learners, students with Individualized Education Plans, and students eligible for Free and Reduced Price Lunch) and setting (state, region, and urbanicity).

The WWC is releasing this free dataset as part of our open data approach to increase transparency and encourage data driven assessments. This dataset will provide:

  • Greater transparency for WWC reviews, allowing users to replicate WWC findings and reports
  • Comprehensive information to encourage research questions beyond those asked by the WWC
  • Detailed study findingsto allow for meta-analysis
  • Contextual information for the examination of what works for whom and under what conditions”


The following keywords and search strings were used to search the reference databases and other sources:

  • Elements (or features) of preschool quality
  • Preschool models and outcomes
  • Preschool and later outcomes
  • Play-based vs. academic (or direct instruction) preschool

Databases and Resources

We searched ERIC for relevant resources. ERIC is a free online library of over 1.6 million citations of education research sponsored by the Institute of Education Sciences (IES). Additional IES sources searched include the Regional Educational Laboratory (REL) Program and National Center for Education Research (NCER). Other search engines used are Google Scholar, Google, and Bing.

Reference Search and Selection Criteria

When we were searching and reviewing resources, we considered the following criteria:

  • Date of the Publication: References and resources published for the last 15 years, from 2002 to present, were included in the search and review.
  • Search Priorities of Reference Sources: Search priority is given to study reports, briefs, and other documents that are published and/or reviewed by IES and other federal or federally funded organizations and academic databases, including ERIC and Google Scholar.
  • Methodology: Following methodological priorities/considerations were given in the review and selection of the references: (a) study types – randomized controlled trials, quasi-experiments, surveys, descriptive data analyses, literature reviews, policy briefs, etc., generally in this order; (b) target population, samples (representativeness of the target population, sample size, volunteered or randomly selected, etc.), study duration, etc.; and (c) limitations, generalizability of the findings and conclusions, etc.

This memorandum is one in a series of quick-turnaround responses to specific questions posed by educational stakeholders in the West Region (Arizona, California, Nevada, Utah), which is served by the Regional Educational Laboratory West at WestEd. This memorandum was prepared by REL West under a contract with the U.S. Department of Education’s Institute of Education Sciences (IES), Contract ED-IES-17-C-00014524, administered by WestEd. Its content does not necessarily reflect the views or policies of IES or the U.S. Department of Education nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. Government.