Background This study focuses on probing preservice technology teachers’ cognitive structures and how they construct engineering design in technology-learning activities and explores the effects of infusing an engineering design process into science, technology, engineering, and mathematics (STEM) project-based learning to develop preservice technology teachers’ cognitive structures for engineering design thinking. Results The study employed a quasi-experimental design, and twenty-eight preservice technology teachers participated in the teaching experiment. The flow-map method and metalistening technique were utilized to enable preservice technology teachers to create flow maps of engineering design, and a chi-square test was employed to analyze the data. The results suggest that (1) applying the engineering design process to STEM project-based learning is beneficial for developing preservice technology teachers’ schema of design thinking, especially with respect to clarifying the problem, generating ideas, modeling, and feasibility analysis, and (2) it is important to encourage teachers to further explore the systematic concepts of engineering design thinking and expand their abilities by merging the engineering design process into STEM project-based learning. Conclusions The findings of this study provide initial evidence on the effects of infusing the engineering design process into STEM project-based learning to develop preservice technology teachers’ engineering design thinking. However, further work should focus on exploring how to overcome the weaknesses of preservice technology teachers’ engineering design thinking by adding a few elements of engineering design thinking pedagogy, e.g., designing learning activities that are relevant to real life.

This study set out to re-examine the effectiveness of study abroad programs in second language (L2) acquisition through a multi-level meta-analysis. Overall, 42 primary studies published between 1995 and 2019 were identified, and in total 283 effect sizes were meta-analysed. This study implemented a three-level random effects model to account for the clustered, mutually dependent effect sizes often nested in the primary studies of L2 study abroad research. The results indicated a medium-to-large effect ( g = 0.87) on study abroad language programs. Essentially, the featured moderators in general explained more heterogeneity variances at level 3 (i.e. the between-study level) than at level 2 (i.e. the within study level). For study abroad language learners, language acquisition is optimal when learners, in particular those of a lower proficiency level, take both formal and content-based language courses while living with host families. Learners’ age and pre-program training may not moderate the effectiveness of study abroad language programs. Importantly, this study further established that the length of study abroad programs are positively associated with learners’ language gains, but that an extended and prolonged domestic program does not necessarily lead to such gains. Research and pedagogical implications are further discussed based on the research findings.