Does Teacher Learning Last? Understanding How Much Teachers Retain Their Knowledge After Professional Development

October - November 1, 2020

Source: Journal of Teacher Education, Volume: 71 issue: 5, page(s): 537-550

(Reviewed by the Portal Team)

Research findings suggest that teachers’ content knowledge (CKT) is a key mediator that is closely connected with both program treatment and student learning and thus should be included for examining the effectiveness and the underlying mechanism of the professional development (PD) programs.
Based on a set of PD programs for mathematics teachers that took place during 2008 to 2013, this study investigates the following two research questions:
Research Question 1: What is the decay rate of content knowledge for teaching mathematics (CKT-M) after teachers complete PD programs?
Research Question 2: If teachers forget what they learn, does the decay rate vary by program features and participant characteristics?
In this study, the authors expand on previous small-scale research by estimating the decay of content knowledge for teaching using a large sample of K-12 math teachers from multiple PD programs representing diverse contexts in the United States.
In addition, the data set contains a set of variables on teacher characteristics and program features, which allows them to examine empirically how some of the factors identified or hypothesized in prior studies affect knowledge decay after teachers complete their PD programs.

Data and Methods

The analytic sample consists of data collected in the Teacher Knowledge Assessment System (TKAS), which is a Web-based platform administering assessments of mathematical knowledge for teaching, developed through the Learning Mathematics for Teaching project at the University of Michigan.
TKAS was launched in June 2008 and has been widely used by researchers, PD providers, teacher educators, and program evaluators to assess teachers’ mathematical knowledge and its development.
The sample only included in-service teachers enrolled in PD programs.
The author only include the 3,340 teachers who made a good faith effort.
The final sample contains a mix of K-12 teachers who differ in education background and teaching experience.
In terms of program characteristics, approximately, half of the programs in the sample span both summer and school year.
Summer institutes account for a slightly larger percentage compared with programs that occur during school year.

Results and discussion
The results show that teacher knowledge is not stable after PD.
In fact, the loss of knowledge, or knowledge decay, does take place, and it may be quite substantial.
If improving student learning is the goal of the PD programs, the focus of these programs should not only be on what teachers learn but also on whether the learning lasts long enough to make it to the classroom.
In addition, the study shows that knowledge decay rate varies considerably across programs, and the decay rate is affected by teachers’ initial knowledge level as well as the design of PD programs (e.g., program type and intensity).

While there is more to learn, results from this study suggest several components of PD programs that are important for sustaining post-training teacher learning.
One important component is the duration of the program.
Prior studies showed that longer duration of PD led to larger improvements in teacher knowledge or teaching practices (Copur-Gencturk & Papakonstantinou, 2016; Garet, Porter, Desimone, Birman, & Yoon, 2001).
Likewise, this study found that programs with greater number of training sessions or longer duration are associated with lower knowledge decay rate, suggesting that longer program duration not only increases the impact of PD on teachers but also sustains the impact afterwards.
Another component is the provision of follow-up activities after intensive training sessions.
The authors found that summer programs have higher knowledge decay than whole year or school year programs.
While alternative explanations are possible, a major difference between these programs is that unlike summer program, whole year or school year programs provide opportunities for teachers to immediately apply new knowledge in their own classrooms.
School year programs also often provide follow-up support to teachers.
These supports are important for teachers to internalize and apply key ideas learned from the training and, as a result, may reduce knowledge decay following the completion of PD.
In designing or implementing teacher PD program, it could be important to consider these findings on knowledge decay together with those design components that improve program effects to increase teacher learning in the short and long run.
In addition to program design, the study informs the design of research studies evaluating the effectiveness of teacher PD.
Policymakers might consider including the sustainability of program effects as another criterion for assessing program effectiveness.
Existing research has found that teacher PD programs can have significant and substantial effects on teacher knowledge, supporting claims by policymakers and researchers that teacher PD training is an important lever toward improving instruction and student learning (Desimone, 2009).
However, to date, research on the effectiveness of these programs has treated the program effects as if they are stable.
This is against the viewpoint from cognitive scientists that knowledge or skills tend to be unstable and changing over time.
The decay of knowledge gains is particularly salient when there is a lack of use of the knowledge acquired (Kim, Ritter, & Koubek, 2013).
Those program evaluation studies that neglect the changing nature of teacher knowledge may provide incomplete or even misleading evidence on the effectiveness of the programs.
This study suggests that it is worthwhile to consider knowledge decay as an equally important factor when designing, implementing, and evaluating programs that support teacher learning.

Copur-Gencturk, Y., & Papakonstantinou, A. (2016). Sustainable changes in teacher practices: A longitudinal analysis of the classroom practices of high school mathematics teachers. Journal of Mathematics Teacher Education, 19(6), 575-594.
Desimone, L. (2009). Improving impact studies of teachers’ professional development: Toward better conceptualizations and measures. Educational Researcher, 38, 181-199.
Garet, M. S., Porter, A. C., Desimone, L., Birman, B. F., & Yoon, K. S. (2001). What makes professional development effective? Results from a national sample of teachers. American Educational Research Journal, 38(4), 915-945.
Kim, J. W., Ritter, F. E., & Koubek, R. J. (2013). An integrated theory for improved skill acquisition and retention in the three stages of learning. Theoretical Issues in Ergonomics Science, 14(1), 22-37. 

Updated: Mar. 15, 2021