In learning from examples, students are often first provided with basic instructional explanations of new principles and concepts and second with examples thereof. In this sequence, it is important that learners self-explain by generating links between the basic instructional explanations' content and the examples. Therefore, it is well established that learners receive self-explanation prompts. However, there is hardly any research on whether these prompts should be provided in a closed-book format-in which learners cannot access the basic instructional explanations during self-explaining and thus have to retrieve the main content of the instructional explanations that is needed to explain the examples from memory (i.e., retrieval practice)-or in an open-book format in which learners can access the instructional explanations during self-explaining. In two experiments, we varied whether learners received closed-or open-book self-explanation prompts. We also varied whether learners were prompted to actively process the main content of the basic instructional explanations before they proceeded to the self-explanation prompts. When the learners were not prompted to actively process the basic instructional explanations, closed-book prompts yielded detrimental effects on immediate and delayed (1 week) posttest performance. When the learners were prompted to actively process the basic instructional explanations beforehand, closed-book self-explanation prompts were not less beneficial than open-book prompts regarding performance on a delayed posttest. We conclude that at least when the retention interval does not exceed 1 week, closed-book self-explanation prompts do not entail an added value and can even be harmful in comparison to open-book ones.

Correct responses to the unitized items of PISA 2006 rely to differing extents on the contextual stimulus supplied. This difference is referred to in this study as the degree of contextualization. A selection of science items from PISA 2006 has been assigned to two categories, not by competencies as in the framework for the PISA survey, but by the degree to which the item requires the ability to extract and apply information from the contextual stimulus provided. The article explores how students in Germany and in other selected OECD countries perform in solving these two types of items. The results show that German students' performance is satisfactory when solving items which require knowledge to be recalled and applied but that they are also quite capable of extracting and using information from the item stimuli. Somewhat different distributions are observed in other selected OECD countries. © 2009 Wiley Periodicals, Inc. J Res Sci Teach 46: 897–908, 2009

This paper presents a study about augmented-reality-based chemistry learning in a university lecture. Organic chemistry is often perceived as particularly difficult by students because spatial information must be processed in order to understand subject specific concepts and key ideas. To understand typical chemistry-related representations in books or literature, sophisticated mental rotation- and other spatial abilities are needed. Providing an augmented reality (AR) based learning support in the learning setting together with text and pictures is consistent with the idea of multiple external representations and the cognitive theory of multimedia learning. Using multiple external representations has proven to be beneficial for learning success, because different types of representations are processed separately in working memory. Nevertheless, the integration of a new learning medium involves the risk to hinder learning, in case of being not suitable for the learning topic or learning purpose. Therefore, this study investigates how the AR-use affects students’ cognitive load during learning in three different topics of organic chemistry. For this purpose also the usability of AR learning support is considered and the possible reduction of the influence of the mental rotation on learning success will be investigated.

Visualizations and visual models are of substantial importance for science learning (Harrison and Treagust, 2000), and it seems impossible to study chemistry without visualizations. More specifically, the combination of visualizations with text is especially beneficial for learning when dual coding is fostered (Mayer, 2014). However, at the same time, comprehending the visualizations and visual models appears to be rather difficult for learners (e.g., Johnstone, 2000). This may be one reason for the difficulties students experience especially during the university entry phase, which in a worst-case-scenario can result in high university drop-out rates as they are currently found in science-related study courses (Chen, 2013). In this regard, our study investigates, how the ability to handle and learn with visualizations – which we call visual model comprehension – relates to academic success at the beginning of chemistry studies. To do so, we collected the data of 275 chemistry-freshmen during their first university year. Our results show that visual model comprehension is a key factor for students to be successful in chemistry courses. For instance, visual model comprehension is able to predict exam grades in introductory chemistry courses as well as general chemistry content knowledge. Furthermore, our analyses point out that visual model comprehension acts as a mediator for the relation between prior knowledge and (acquired) content knowledge in chemistry studies. Given this obvious importance of visual model comprehension, our findings could give valuable insights regarding approaches to foster chemistry comprehension and learning especially for students at the beginning of their academic career.

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