The Common Core State Standards (CCSS)—or simply, the Common Core—consist of a set of benchmarks for what students in elementary and secondary schools should master in mathematics and English language arts (ELA) at each grade level. Since their release in 2010, the standards have been adopted in more than 40 states, including all of New England. And almost since the beginning, the standards—and the new assessments developed to test student knowledge of them—have provoked heated debate. Conservative lawmakers have argued that the standards constitute federal overreach into local policy matters. Some teachers’ unions and parent organizations have protested the burdens that standardized testing imposes on students and teachers.

For most states, the Common Core constituted a considerable departure from the previous generation of standards. The mathematics standards, for example, required changes in the timing, depth, and frequency with which topics are addressed across grades. For instance, students now begin multiplication of fractions in fourth grade and are expected to be fluent by the end of fifth grade—a grade level earlier than before in most states. More than any other education initiative in recent history, the Common Core has required teachers to change their instructional focus, practices, and curricular materials. Education leaders have had to grapple with challenges like developing curricula aligned with the new standards and bridging gaps in teachers’ content knowledge in a relatively short amount of time.

To learn more about how educators were implementing the Common Core, in the spring of 2015 the Center for Education Policy Research at Harvard University surveyed principals and mathematics and ELA teachers in 151 elementary and middle schools across five states (Delaware, Maryland, Massachusetts, New Mexico, and Nevada). The sample was designed to be representative of public schools in each of the five states. We solicited educators’ views on the standards, the training, and the supports they received in adjusting their teaching and curricular materials, among other topics. Overall, 1,498 teachers and 142 principals completed the surveys, equivalent to response rates of 86 percent for teachers and 93 percent for principals.

We also studied whether teachers’ exposure to strategies and supports designed to facilitate implementation of the Common Core was related to better student performance on the new CCSS-based assessments (Partnership for Assessment of Readiness for College and Careers, or PARCC, and Smarter Balanced), after accounting for numerous student, school, and teacher characteristics. This article summarizes key findings from this research.¹

What Teachers and Principals Reported

Educators’ support is instrumental to the success of any education initiative. If teachers are unconvinced of the standards’ potential to improve students’ performance, they may be less inclined to invest time and effort in overhauling their instruction. The surveys revealed that teachers and principals in the five states have largely embraced the Common Core standards and believe that their schools are effectively implementing them. Almost three quarters of teachers (73 percent) reported that teachers in their school have embraced the CCSS “quite a bit” or “fully”; about 90 percent said the same of their principal and district administrators. (See “Teacher and Administrator Support for CCSS.”) In a separate question, 69 percent of principals agreed the CCSS “will have a positive effect on student learning in the long run.” Moreover, more than eight out of 10 teachers agreed that their colleagues (81 percent) and their principal (83 percent) were implementing the standards effectively; about three quarters (73 percent) reported the same for their district leaders.

Teachers also shared that they have made major changes to their instruction and materials to adjust them to the Common Core. Eighty-two percent of mathematics teachers and 72 percent of ELA teachers reported having changed at least half of their instructional materials as a result of the CCSS. Three quarters of teachers (76 percent) also reported having changed at least half of their classroom instruction. (See “Changes in Instruction and Materials.”) When asked about specific instructional shifts emphasized by the Common Core, the vast majority (81 percent) of mathematics teachers reported an increased emphasis on students’ conceptual understanding of mathematics; 78 percent increased the time students spend on real-world application of mathematical knowledge. Among ELA teachers, 86 percent reported having increased the amount of assigned writing that prompts students to support their views with evidence. Similarly, 85 percent of ELA teachers reported increased use of nonfiction texts in students’ reading assignments.

Given the vast changes in instructional practices and materials necessitated by the Common Core, it is not surprising that educators reported receiving substantial training on several CCSS-related topics, such as developing aligned materials or mastering new pedagogic techniques. In the early spring of 2015, teachers and principals reported having spent on average 3.8 days and 4.5 days, respectively, in formal professional development on the Common Core so far that year. The average teacher and principal also reported spending 4.5 days and 5.3 days, respectively, in CCSS-focused professional development the previous school year (2013–2014). More than half of all teachers reported that staff from their own schools were the primary providers of Common Core professional development.

While important, formal professional development alone may not be sufficient to prepare teachers. Observing teachers apply CCSS-consistent instructional techniques in the classroom, providing them with feedback, and helping them troubleshoot reinforces lessons learned in formal training. While the vast majority of teachers (89 percent) were observed in the classroom at least once in 2014–2015, less than half (47 percent) reported receiving explicit feedback afterward on how well their instruction matched Common Core expectations. And only 44 percent reported that they could identify specific instructional changes they made as a result of that feedback.

Finally, in many states nationwide, the evaluation of teachers incorporates measures of students’ achievement. If these measures were tied to the Common Core, it could potentially give teachers added incentives to adjust their practices and materials. To shed more light, we asked teachers whether their students’ performance on PARCC, Smarter Balanced, or other CCSS-aligned assessments played a role in their formal performance evaluation in 2014–2015. Half of all teachers reported that it did. This share was particularly high—at 87 percent—in New Mexico, the only state in the study in which students’ 2014–2015 PARCC test scores factored into teachers’ performance evaluations. (In the remaining states, the CCSS-aligned student outcomes came from interim assessments, district assessments, or student learning objectives.)

What Has Worked?

A novel feature of our study design is our ability to link teachers’ survey responses to their students’ test scores on the 2014–2015 PARCC and Smarter Balanced assessments, as well as to state data on students’, teachers’, and schools’ characteristics and students’ prior academic performance. This enables us to observe whether a teacher’s exposure to a Common Core support was associated with better performance among her students, compared with the performance of students whose teachers did not receive such support, while controlling for a large array of factors that also affect student performance.

In mathematics, we identified three promising CCSS implementation strategies: more professional development days, more classroom observations followed by feedback tied to the Common Core, and the inclusion of Common Core–aligned student outcomes in teacher evaluations. All three strategies were associated with higher student achievement on the PARCC and Smarter Balanced assessments in mathematics, controlling for students’ demographic characteristics, teacher and school factors, and students’ prior performance on non-CCSS assessments.

In ELA, we were unable to point to any strategies that correlated with students’ performance. However, our results suggest that the new English assessments are more sensitive to instructional differences between teachers than the old ELA assessments, especially in middle school. This appears to be due to the fact that the new assessments place greater weight on student writing. While prior research on the old assessments deemed mathematics tests more sensitive than ELA tests to differences between teachers, the new CCSS-aligned English assessments appear nearly as sensitive as the new mathematics assessments. This finding has important implications for practice. If the new ELA tests do identify teachers who are more successful at developing student writing, school districts will be better able to reward and retain those teachers. Districts will also be able to measure the impacts of professional development and other supports that help teachers improve students’ writing skills, thereby informing better and more cost-effective programming choices.

Over the past few years, while the battle over the Common Core has raged, teachers have quietly retooled their practices, lesson plans, and materials to meet the new standards. The findings in this research provide a starting point for locating effective ways of supporting teachers in implementing the Common Core and lay a foundation for future research that digs deeper into what works and what doesn't.

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