People increasingly use videos on the Web for learning, be it for daily tasks in formal or informal educational settings. To enhance this type of learning, scientists are continuously conducting experiments, proposing guidelines, analyzing data, and researching artificial intelligence methods for tool development. In this comprehensive review, we analyze 257 articles (using PRISMA guidelines) on video-based learning from a technological perspective for the period from 2016 to 2021. One of the aims is to identify video characteristics that support learning as explored by previous research. Based on our analysis, we suggest a taxonomy that organizes the video characteristics and contextual aspects into eight categories: (1) audio features, (2) visual features, (3) textual features, (4) instructor behavior, (5) learners’ activities (play, pause, etc.), (6) interactive features (quizzes, etc.), (7) production style, and (8) instructional design. Also, we identify four representative methodological approaches: (1) tool support of video-based learning, (2) controlled experiments, (3) data analysis studies, and (4) design guidelines for learning videos. We find that the most explored characteristics are textual features followed by visual features, learners’ activities, and interactive features. Tools that aid learning through videos frequently utilize text from transcripts, video frames, and images. The learner’s activity is heavily explored through log files in data analysis studies, and interactive features are frequently scrutinized in controlled experiments. As further contributions, we contrast research findings on how video characteristics affect learning effectiveness, report on tasks and technologies used to develop tools, and summarize design guideline trends to produce learning videos. Our findings provide actionable insights for the design of intelligent educational systems that better support video-based learning.

Teaching and learning chemistry or science, in general, could be described as building upon learners' existing conceptions. In order to support individual conceptual development, teachers should create opportunities for students to become aware of their thoughts. As this is very demanding in chemistry classroom practice with twenty-five or more individuals, pedagogical approaches and instructional support are needed. We argue for a collaborative learning practice that focuses on sharing and discussing individual conceptions on a chemistry-based phenomenon to build up a joint conceptual understanding. We state seven essential features for integrating this collaborative pedagogy successfully in classroom practice: (1) Becoming aware of one's own conceptions; (2) externalizing individual ideas; (3) initiating comparable situation models; (4) ensuring active involvement of all; (5) offering each learner opportunities to reflect on each other's conceptual understanding; (6) integrating decision-making processes; (7) offering the teacher measures to monitor the learning process. This paper is structured in three parts. Part I gives theoretical evidence to these essential features. Part II introduces the peer-interaction-method (PIM) as one of the possible collaborative learning approaches. The PIM is a pre-structured two-step collaborative learning method with instructional measures to meet the seven features. Part III reports a study with 136 students (grade 8 and 9), learning with the PIM in the context of combustion. The results give evidence to the features as being promising to foster individuals’ conceptual development in science learning. The paper concludes with a discussion, limitations and an outlook for further studies and pedagogies in the context of developing conceptual understanding in collaborative settings.

Intelligent tutoring system (ITS) provides learners with step-by-step problem-solving support through scaffolding. Most ITSs have been developed in the USA and incorporate American instructional strategies. How do non-American students perceive and use ITS with different native problem-solving strategies? The present study compares Stoich Tutor, an ITS with a high level of scaffolding, with ORCCA, an ITS with dynamic scaffolds that can support a range of problem-solving strategies. We conducted a think-aloud study with university students in the USA (N = 10) and Germany (N = 11), where students worked with either Stoich Tutor and ORCCA before solving stoichiometry problems on paper. Two human coders derived a coding scheme to investigate the strategies American and German students employ during problem solving on paper without instructional support. We derive a taxonomy of three stoichiometry problem-solving strategies. Next to the American factor labeling method, this taxonomy includes a strategy based on equation transformations and a previously undocumented strategy using abstract symbols to isolate a target variable and then pluck in given values and compute the solution. German students exclusively used the latter strategy, which was not explicitly supported by any of the two tutoring systems. Further, students who did not use the factor-label method for paper-based problem solving, most of whom were German, initially had difficulty setting appropriate goals and working with fractions in the Stoich Tutor. While German students preferred ORCCA based on short interviews, they more often successfully solved problems in Stoich Tutor. Therefore, Stoich Tutor, although misaligned with German instruction, could still support German students’ learning. Still, revisions to ITS based on local instructional cultures could make them potentially more effective and aligned with curricular goals.

Chemistry is a science that not only examines substances at different levels of abstraction and involves a wide multitude of cognitive and experimental operations, but also used and uses a variety of concepts and representations referring to the same term. At the same time, many studies on the professional competencies of teachers underline the importance of content knowledge as a prerequisite for pedagogical content knowledge and instructional quality for example. While these studies use a quantitative logic of more or less chemistry knowledge, this paper argues that teachers do not only have to understand chemical concepts but also have to be able to manage conceptual plurality. This involves explaining phenomena based on different concepts, comparing their explanatory power and their limitations, and reflecting upon their sometimes different ontological and epistemological status. We propose conceptual clarifications for acid–base chemistry, redox chemistry, and atomic and bonding models to indicate how plurality manifests itself in chemistry in the first place. On this basis, we derive five approaches showing how managing conceptual plurality in chemistry helps to support learning chemistry. Teachers are more likely to make adequate curricular decisions, to anticipate students’ conceptions, to support transitions between concepts meaningfully, or to foster epistemic cognition as a part of learning chemistry. We discuss these approaches as explanations for findings in the field of teachers’ professional competencies.