The spring knowledge impact was larger for teachers with higher baseline knowledge: significant for teachers 1 SD above average (34 percentile points) but not 1 SD below (8 points)¶

Claim · All claims
Evidence · 1 study (2 entries) · causal r3 · q4
Currency · newest study 2016 · not yet checked against its sources · not reviewed by a person

Subclaims¶

q4 i? The estimated spring impact was positive and statistically significant for teachers with baseline knowledge 1 SD above average (improvement index of 34 percentile points) but not for teachers 1 SD below average (8 percentile points). → Garet 2016 q4 i? Fall impacts did not differ by baseline knowledge (25 vs 23 percentile points, both significant), indicating the initial boost was not sustained for lower-knowledge teachers. → Garet 2016 (2)

Evidence¶

Garet 2016¶

Garet, M. S., Heppen, J. B., Walters, K., Parkinson, J., Smith, T. M., Song, M., Garrett, R., Yang, R., & Borman, G. D. (2016). Focusing on mathematical knowledge: The impact of content-intensive teacher professional development, executive summary (NCEE 2016-4009). Washington, DC: National Center for Education Evaluation and Regional Assistance, Institute of Education Sciences, U.S. Department of Education. http://ies.ed.gov/ncee

q4 · i? · causal · r3

Moderator analysis within the RCT using baseline knowledge scores standardized with the control-group mean and SD. The report states the initial boost was not sustained for teachers who began with lower levels of knowledge, even with school-year supports.

"the impact of the PD on teachers' knowledge in the spring was larger for teachers with higher baseline knowledge scores than for teachers with lower baseline scores"

Garet 2016 (2)¶

Garet, M. S., Heppen, J. B., Walters, K., Parkinson, J., Smith, T. M., Song, M., Garrett, R., Yang, R., & Borman, G. D. (2016). Focusing on mathematical knowledge: The impact of content-intensive teacher professional development, executive summary (NCEE 2016-4009). Washington, DC: National Center for Education Evaluation and Regional Assistance, Institute of Education Sciences, U.S. Department of Education. http://ies.ed.gov/ncee

q4 · i? · causal · r3

Fall moderator analysis from the same trial, showing similar significant impacts at both baseline levels before the school-year supports were delivered.

"The estimated impact of the PD on fall teacher knowledge was positive and statistically significant for teachers with a baseline knowledge score 1 standard deviation above average (improvement index of 25 percentile points) as well as for teachers 1 standard deviation below average (improvement index of 23 percentile points)"

Discussion¶

Related Claims¶

• A 93-hour content-intensive math PD program improved fourth-grade teachers' math content knowledge — related
• The PD did not improve fourth-grade student math achievement; treatment students scored 2 percentile points lower on both measures — related
• Content-intensive math PD produced a statistically significant, sustained gain in grade 4 teachers' math content knowledge (21 percentile points in spring) — a broader claim this one bears on
• The PD's spring impact on teacher knowledge was larger for teachers with higher baseline knowledge and not significant for those 1 SD below average — possibly the same claim (merge candidate)