Martine van der Pluijm

117 How can teachers build partnerships? finding is in line with our observations in the schools. We observed that teachers’ active role towards parents is often a personal choice, which is insufficiently supported by school policy (see also Chapter 3; Epstein et al., 2019). This situation where innovative teacher behavior is not embedded in school policy might undermine sustainable changes in professional behavior (Van Veen et al., 2012). Overall, the AHL program resulted in improved SFPs for young children’s oral language development and in increased motivations of teachers to engage parents. These findings are complementary to our recent findings (see Chapter 5.) that evaluated how AHL contributed to parental oral language support. The studies together show promising directions to further contribute to SFPs directed at the parents and children that are most in need of this support. Limitations and suggestions for future research In this study, we prioritized gaining in-depth understanding of how the AHL program influences teachers’ behavior and their feelings of ownership. The program is based on seven design principles that were developed in the previous design and literature research (see Chapter 3; Van der Pluijm et al., 2019). The present study is the first step to investigate whether the seven design principles of the AHL program can be used by other teachers who work with high numbers of lower-educated parents. This approach has limitations due to the small sample of selected teachers that participated in this study and the absence of a control condition. Therefore, a recommendation for future research is to investigate whether the AHL principles can be generalized by experimental research that includes a control group. We recommend a phased research design that creates control groups by using a switching replications design (Trochim, Donally, & Aurora, 2014). In other words, all teachers in organizations will participate in the program. By phasing implementation, we can compare the results of groups with and without the program one after the other. This type of design will create opportunities to implement the program step-by-step, and formgroups of teachers according to their motivation and possibilities at that moment. The first experiment groups may need more motivation and feelings of self-efficacy to become involved, because of the content that is relatively unfamiliar at that stage. The good examples of the first group can then show the benefits of participating in the experiment and motivate teachers who were initially more hesitant to become actively involved. If more evidence is found for the effectiveness of the design principles in the next phase of the experimental research, researchers can consider a random assignment of teachers to research conditions. Implications for policy and practice In this study, teachers managed to build SFPs in support of child language development. Teachers adapted their interventions to the needs of lower-educated parents, using a step-