According to well-known models, self-regulated learning refers to a conceptual framework which integrates cognitive, metacognitive, and regulative components into a self-regulated learning process. Self-regulated learning means the ability to actively plan, implement, monitor, and control one's own learning process and take responsibility for it (Zimmerman & Moylan, 2009). However, studies show that learners might struggle to regulate their learning processes. Therefore, teachers play a crucial part in promoting self-regulated learning (Dignath & Veenman, 2020). According to the cognitive apprenticeship model developed by Collins, Brown, and Newman (1987) teachers can promote competencies like self-regulated learning skills directly by modelling and teaching the students specific self-regulated learning strategies. Based on individually adapted coaching and scaffolding teachers encourage and support learners to self-regulate their learning on their own. Also, they can promote self-regulated learning indirectly by creating and adjusting learning environments that invite students to self-regulate their learning (Dignath & Veenman, 2020). In their study based on video-recorded classroom observations and interviews Dignath & Büttner (2018) show that teachers use rather little time to promote self-regulated learning in general. Furthermore, teachers primarily promote cognitive strategies of self-regulated learning and neglect metacognitive strategies (Dignath & Büttner, 2018).

In recent years, most studies have explored the technology-enhanced promotion of self-regulated learning with adult learners. Various research findings have shown that self-regulated learning processes can be promoted using digital media, for example by implementing online learning environments, MOOCS (Wong et al., 2019) or scaffolding processes in computer-based learning environments (Devolder, van Braak, & Tondeur, 2012). However, there is a paucity of knowledge about the effectiveness of the use of such technology-enhanced teaching settings for learners at K-12 level regarding the teachers' role in promoting self-regulated learning in a direct or indirect way and the interaction between teacher and learner related to the following aspects: achievement support, motivational support, social-emotional support, and relational support (Hagenauer, Hascher, & Volet, 2015).

The systematic review aims at providing an overview of studies on promoting self-regulated learning with digital media among learners at K-12 level. The focus of the systematic review is on the teachers' effectiveness and the teachers' role in this context. Thus, the research questions are formulated as follows:

• What is known about the teachers’ role regarding the effectiveness of the digitally supported promotion of the cognitive, metacognitive, and regulative components of self-regulated learning?
• How can teacher instruction and promotion of self-regulated learning effectively be embedded in technology-enhanced teaching settings?
• How is teachers' effectiveness in a technology-enhanced teaching setting regarding achievement support, motivational support, social-emotional support, and relational support of self-regulated learning according to the conceptual model of Hagenauer, Hascher, & Volet (2015)?
• How does the effectiveness of the promotion of self-regulated learning with digital media depend on the design of instruction?
• How can self-regulated learning skills be promoted in learners at K-12 level with digital media?
• What do the findings of the review mean for teaching practice and teaching effectiveness and for further research on promoting of self-regulated learning and the teachers' role in technology-enhanced teaching settings?

Developing self-regulated skills of K-12 learners is likely to become even more prominent in academic research during the Covid-19 pandemic. Thus, researchers and practitioners need to know which aspects of digital media foster self-regulated learning processes and how self-regulated learning of the students can be promoted.

The review points out the extent of the effectiveness of technology-enhanced teaching in the field of promotion of self-regulated learning. A specific focus is on teachers' role. The results of previous studies integrated in this systematic review represent a starting point for further studies.

To answer the research questions, we conducted a systematic review and analyzed existing studies published in the last 20 years regarding the promotion of self-regulated learning with digital media in learners of K-12 level. A specific focus is on teachers' role in this context. The systematic review followed the PRISMA Flow Diagram developed by Moher et al. (2015) which designates four steps to identify relevant studies: 1) Identification: The initial search aimed to identify the greatest possible number of relevant, international scientific and academic articles, book-chapters, as well as gray literature regarding the research questions. The search string was developed and enhanced based on the theory of self-regulated learning with digital media (Devolder et al., 2012; Dignath & Veenman, 2020; Wong et al., 2019; Zimmerman & Moylan, 2009). The following relevant databases were scanned using a search string with search terms. ERIC for publications in the field of educational science and APA PsychINFO, PSYNDEX, and Scopus for publications in psychology of education. The search was conducted in more than one database in order to avoid omitting key studies of interest published in databases of other disciplines (Gough, Oliver & Thomas James, 2017). 2) Screening: For the first screening based on titles, abstracts, keywords, and subject headings of the texts the following criteria are used: 1) Studies using the concept of self-regulated learning, 2) description of direct or indirect promotion of self-regulated learning, 3) integration of digital media, and 4) analyzing levels of K-12 as a random sample. 3) Eligibility: The eligibility-screening (Moher et al., 2015) is based on the full text of the retrieved studies. In this third step, the above criteria are used again. A further criterion is the teacher's role. The references and bibliographies of the studies included in the final version are scanned as well. 4) Studies included: In the fourth step, the definitive studies integrated in the review are described, systematized, and synthesized regarding the above-mentioned criteria.

Our initial evaluation of the studies indicates that there are various digital approaches to promote self-regulated learning at the K-12 level. For example, students can be directly introduced to self-regulated learning by using digital scaffolds (Kinnebrew & Biswas, 2011; Lam, 2016) or e-portfolios (Romero, Saucedo, Caliusco, & Gutiérrez, 2019) embedded in a well-designed digital learning environment. Lam (2016) uses the example of teaching chemistry at high-school to show the importance of scaffolding for promoting metacognitive components of self-regulated learning. Kinnebrew & Biswas' study (2011) focuses on learning-by-teaching environment where learners have to take on the role of a teacher to teach a virtual learner named Betty. With the help of adaptive scaffolding and feedback the digital learning environment is designed to support students to understand scientific topics on their own while teaching a virtual learner. Romero et al. (2019) present a conceptual model of an intelligent system with ePortfolios to promote self-regulated learning. Preliminary results also show that interactions between teachers and learners are important. Teachers' modeling and instruction of learning strategies and their support and feedback during the learning process are crucial and cannot be replaced by digital media (Lam, 2016). Also, it was found that teachers' modeling, instruction, and promotion of self-regulated learning strategies can be supported by digital media (Lam, 2016). Thus, the findings of the review show possible research gaps to conduct further studies regarding teachers' effectiveness in promoting self-regulated learning in technology-enhanced teaching settings.

Collins, A., Brown, J. S., & Newman, S. E. (1987). Cognitive apprenticeship: Teaching the craft of reading, writing and mathematics. Technical Report, University of Illinois at Urbana-Champaign, 403. Devolder, A., van Braak, J., & Tondeur, J. (2012). Supporting self-regulated learning in computer-based learning environments: systematic review of effects of scaffolding in the domain of science education. Journal of Computer Assisted Learning, 28(6), 557–573. Dignath, C., & Büttner, G. (2018). Teachers’ direct and indirect promotion of self-regulated learning in primary and secondary school mathematics classes - insights from video-based classroom observations and teacher interviews. Metacognition Learning, 13, 127–157. Dignath, C., & Veenman, M. V. J. (2020). The role of direct strategy instruction and indirect activation of self-regulated learning - evidence from classroom observation studies. Educational Psychology Review. Gough, D., Oliver, S., & Thomas James. (2017). An introduction to systematic reviews. Los Angeles: SAGE. Hagenauer, G., Hascher, T., & Volet, S. E. (2015). Teacher emotions in the classroom: associations with students’ engagement, classroom discipline and the interpersonal teacher-student relationship. European Journal of Psychology of Education, 30(4), 385–403. Kinnebrew, J. S., & Biswas, G. (2011). Modeling and measuring self-regulated learning in teachable agent environments. Journal of E-Learning and Knowledge Society, 7(2), 19–35. Lam, C. M. (2016). The roles of instruction and metacognition in enhancing self-regulated learning in a computer-based learning environment: an intervention programme for high school chemistry. Dissertation Abstracts International Section A: Humanities and Social Sciences, 76(10-A(E)). Moher, D., Shamseer, L., Clarke, M., Ghersi, D., Liberati, A., Petticrew, M., et al. (2015). Preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) 2015 statement. Systematic Reviews, 4(1), 1–9. Romero, L., Saucedo, C., Caliusco, M. L., & Gutiérrez, M. (2019). Supporting self-regulated learning and personalization using ePortfolios: a semantic approach based on learning paths. International Journal of Educational Technology in Higher Education, 16(1). Wong, J., Baars, M., Davis, D., Van Der Zee, T., Houben, G.-J., & Paas, F. (2019). Supporting self-regulated learning in online learning environments and MOOCs: a systematic review. International Journal of Human-Computer Interaction, 35(4–5), 356–373. Zimmerman, B. J., & Moylan, A. (2009). Self-regulation: where metacognition and motivation intersect. In D.J. Hacker, J. Dunlosky & A.C. Graesser (Eds.), Handbook of Metacognition in Education (S. 299–315). New York: Routledge.