In a large California study, principals' preparation quality and professional development access predicted teacher retention and student achievement gains¶

Claim · All claims
Evidence · 1 study (3 entries) · review r2 · q2
Currency · newest study 2026 · checked against its sources 2026-10-20 (automated, 3 of 3 entries) · not reviewed by a person

Subclaims¶

q2 i? Teachers' probability of remaining through the following year was 89% under well-prepared principals versus 78% under poorly prepared principals. → Darling-Hammond 2026 q2 i? Mathematics learning differentials for historically underserved students whose principals had little versus extensive instructional-leadership training were equivalent to approximately 4 months of instruction. → Darling-Hammond 2026 (2) q2 i? Students in schools led by early-career principals with extensive professional development showed greater mathematics gains than students under more senior principals with similar access; the study reports this as an association, not a demonstrated effect of the professional development. → Darling-Hammond 2026 (3)

Evidence¶

Darling-Hammond 2026¶

Darling-Hammond, L., Fitz, J., Giani, M. V., Gordon, M. F., & Wechsler, M. (2026). The principal effect: How investing in school leaders is key to solving education's challenges. Learning Policy Institute. https://doi.org/10.54300/644.197

q2 · i? · review · r2

A large-scale California study reported in the review found principals with high-quality preparation had better teacher retention than peers with low-quality preparation, controlling for teacher traits and school conditions: "was 89%" versus "dropped to 78%."

"The probability of a teacher remaining through the following year in a school served by a well-prepared principal was 89%, whereas the likelihood of remaining in a school served by a poorly prepared principal dropped to 78%."

Darling-Hammond 2026 (2)¶

Darling-Hammond, L., Fitz, J., Giani, M. V., Gordon, M. F., & Wechsler, M. (2026). The principal effect: How investing in school leaders is key to solving education's challenges. Learning Policy Institute. https://doi.org/10.54300/644.197

q2 · i? · review · r2

In the California study, students of color from historically underserved communities experienced the largest gains, especially with principals having substantial instructional-leadership professional development; the differential was "equivalent to approximately 4 months of instruction."

"The differentials in mathematics learning for historically underserved students who had a principal with little versus extensive training in this area, for example, were equivalent to approximately 4 months of instruction."

Darling-Hammond 2026 (3)¶

Darling-Hammond, L., Fitz, J., Giani, M. V., Gordon, M. F., & Wechsler, M. (2026). The principal effect: How investing in school leaders is key to solving education's challenges. Learning Policy Institute. https://doi.org/10.54300/644.197

q2 · i? · review · r2

The California study found that students in schools led by early-career principals with extensive professional development showed mathematics gains "greater than those in schools led by more senior principals with similar access to professional development," The report says these results show intensive PD can help close the gap for new principals, but the comparison is an association between principals' reported PD and their students' gains and does not establish that the PD caused them.

"students in schools led by early-career principals who experienced extensive professional development—including on instructional leadership, teaching diverse learners, and managing change—demonstrated achievement gains in mathematics greater than those in schools led by more senior principals with similar access to professional development."

Discussion¶

Related Claims¶

• Principals' instructional leadership practices are linked to improved student outcomes, largely through their support for teachers — the general claim this finding bears on, with the studies behind it
• Principals' overall preparation quality is positively and significantly related to teacher retention, with significant components for developing people and meeting needs of diverse learners — possibly the same claim (merge candidate)
• Principals' professional development access is positively but not significantly related to teacher retention — reports the opposite
• Principals' access to professional development is significantly associated with teacher retention and student achievement, with gains greatest for historically underserved students — possibly the same claim (merge candidate)
• High-quality principal preparation and professional development programs are associated with positive principal, teacher, and student outcomes — a broader claim this one bears on
• State policy differences shape principals' access to high-quality learning: California principals report more access than national peers, North Carolina principals less — related
• Principals with access to high-quality professional learning opportunities are more likely to stay in the profession — related
• Teachers are more likely to stay in schools where they perceive colleagues as collaborators, feel influence over their work environment, and trust their principal as an instructional leader — related
• Principals' access to professional development is positively related to student gains in both ELA and mathematics, with the strongest and most consistent relationships in mathematics — a narrower finding that bears on this claim
• School leaders in higher-wealth schools are more likely to attend high-quality principal preparation programs, creating inequitable access — related