Research has demonstrated that oral explaining to a fictitious student improves learning. Whether these findings replicate, when students are writing explanations, and whether instructional ...explaining is more effective than other explaining strategies, such as self-explaining, is unclear. In two experiments, we compared written instructional explaining to written self-explaining, and also included written retrieval and a baseline control condition. In Experiment 1 (N = 147, between-participants-design, laboratory experiment), we obtained no effect of explaining. In Experiment 2 (N = 50, within-participants-design, field-experiment), only self-explaining was more effective than our control conditions for attaining transfer. Self-explaining was more effective than instructional explaining. A cumulating meta-analysis on students’ learning revealed a small effect of instructional explaining on conceptual knowledge (g = 0.22), which was moderated by the modality of explaining (oral explaining > written explaining). These findings indicate that students who write explanations are better off self-explaining than explaining to a fictitious student.
•We compared writing instructional explanations to self-explaining and retrieval.•Self-explaining lead to better test performance than retrieval.•Self-explaining was also more effective than instructional explaining.•Meta-analytic evidence showed only benefits for oral but not written explaining.
In this experiment, we examined whether linguistic text complexity affects effects of explaining modality on students’ learning. Students (N = 115) read a high-complex and a low-complex text. ...Additionally, they generated a written or an oral explanation to a fictious peer. A control group of students retrieved the content. For the low-complex text, we found no significant differences between conditions. For the high-complex text, oral explaining yielded better comprehension than writing explanations. The retrieval condition showed the lowest performance. Mediation analyses revealed that the effect of explaining modality while learning from the high-complex text was mediated by the personal references and the comprehensiveness of the generated explanations. Our findings suggest that the effect of explaining modality emerges when students are required to learn from difficult texts. Furthermore, they show that oral explaining is effective as, likely due to increases of social presence, it triggers distinct generative processes during explaining.
•Explaining modality (written vs. oral) showed to inconsistently affect learning.•We tested whether explaining modality depends on text complexity.•Oral explaining was best for high-complex, but not for low-complex texts.•Personal references and the comprehensiveness of explanations were crucial for learning.
Writing explanations has demonstrated to be less effective than providing oral explanations, as writing triggers less amounts of perceived social presence during explaining. In this study, we ...investigated whether increasing social presence during writing explanations would aid learning. University students (N = 137) read an instructional text about immunology; their subsequent task depended on experimental condition. Students either explained the contents to a fictitious peer orally, wrote their explanations in a text editor, or wrote them in a messenger chat, which was assumed to induce higher levels of social presence. A control group retrieved the material. Surprisingly, we did not obtain any differences in learning outcomes between experimental conditions. Interestingly, explaining was more effortful, enjoyable, and interesting than retrieving. This study shows that solely inducing social presence does not improve learning from writing explanations. More importantly, the findings underscore the importance of cognitive and motivational conditions during learning activities.
Asking students to generate explanations to fictitious others by means of different technologies (e.g., instant messenger, video) has gained popularity in schools. Although the potential of these ...technology-mediated explaining activities is appealing, less is known whether generating these explanations is effective for school students. Additionally, empirical evidence regarding general effects of learning-by-explaining proposes that generating explanations is constrained by different boundary conditions. In this experimental field study, we investigated the effectiveness of technology-mediated explaining with seventh grade students (N = 129). More importantly, we contrasted different implementation modalities of explaining (i.e., written versus oral explaining) and examined the moderating role of cognitive and motivational prerequisites (i.e., prior knowledge, academic self-concept). After assessing prior knowledge and academic self-concept, students attended a lesson on photosynthesis. Then, students were randomly assigned to explain the contents in written versus oral form in a mock-up messenger or to retrieve the contents by taking notes (control condition). We neither obtained an effect of explaining, nor did the explanatory modality account for students' learning. However, exploratory moderation analyses showed that academic self-concept but not prior knowledge moderated the explaining effect on comprehension, as only students with low self-concept profited from explaining. In contrast, students with high self-concept benefited most from retrieving the provided contents. The findings highlight that technology-mediated explaining is not necessarily an effective learning activity for school students, but might depend on students’ motivational prerequisites, such as their academic self-concept.
•In an experiment with secondary students, we explored effects of explaining.•Learning-by-explaining was moderated by self-concept but not prior knowledge.•Low academic self-concept students profited more from explaining than retrieval.•High academic self-concept students benefited more from retrieving than explaining.•There was no main effect of explaining regardless of modality.
Background
Engaging students in computer‐assisted guided inquiry learning has great potential to scaffold their scientific understanding: Students are expected to improve their scientific ...problem‐solving skills, and at the same time gain a deep conceptual understanding of the subject‐matter. Additional generative activities such as creating video explanations subsequent to inquiry learning activities can also further deepen students' knowledge.
Objectives
In this experiment, we therefore compared the effectiveness of computer‐based direct instruction (to mimic traditional classroom teaching) versus computer‐based inquiry learning.
Methods
University students (N = 118) either received video‐based direct instruction (direct instruction), including the demonstration of a virtual experiment, or conducted the virtual experiment themselves supported by prompts (inquiry learning). A third group of students additionally generated a video explanation as consolidation activity subsequent to conducting the virtual experiment (inquiry learning + generative activity).
Results and Conclusions
Contrarily to our hypotheses, the direct instruction condition outperformed the inquiry learning conditions. There were no significant differences between the inquiry learning and the inquiry learning + generative activity condition. Moderation analyses revealed that the effectiveness of direct instruction predominantly held true for students with low levels of domain‐specific self‐concept. All in all, our present study contributes to a better understanding of effects of direct instruction versus guided inquiry learning in computer‐based science education settings. Importantly, our findings show that the effectiveness of instructional approaches may depend on students' domain‐specific self‐concept as a motivational prerequisite. As such it is up for further research in science education to identify motivating instructional strategies to enhance students' learning.
Lay Description
What is already known about this topic
Computer‐assisted guided inquiry learning has great potential to scaffold students' scientific understanding.
However, inquiry learning can be cognitively overwhelming, particularly for novice students.
Direct instruction is frequently discussed as an alternative to inquiry learning, as students are explicitly taught on the subject‐matter content.
What this paper adds
We investigated (a) the effectiveness of three different computer‐based instructional approaches including inquiry learning and direct instruction and (b) the role of students' cognitive and motivational prerequisites.
Contrary to our hypotheses, students in the guided inquiry conditions did not outperform those in the direct instruction condition.
Moreover, especially students with a low domain‐specific self‐concept profited from direct instruction compared to inquiry learning.
Implications for practice and/or policy
All in all, our present study contributes to a better understanding of effects of direct instruction versus guided inquiry learning in computer‐based science education settings.
Importantly, our findings show that the effectiveness of instructional approaches may depend on students' domain‐specific self‐concept as a motivational prerequisite.
As such it is up for further research in science education to identify motivating instructional strategies to enhance students' learning.
Against the backdrop of preparing students for a digitalized future, supporting pre-service teachers' development of technological pedagogical content knowledge (TPACK) has become paramount in ...pre-service teacher education. Whether and how pre-service teachers' acquisition of TPACK could be supported is still an open question, as previous research predominantly relied on correlational data and/or self-report assessments. Based on previous research, we developed subject-specific versions of a TPACK-module to support the acquisition of TPACK. Further purpose of the TPACK-module was to enhance technology-related motivation, as motivational orientations have been documented to be crucial for technology integration. We evaluated the effectiveness of the module by means of a quasi-experimental field study. Pre-service teachers (N = 208), enrolled in five subjects, attended regular semester courses on subject-matter pedagogies. In half of the courses, we randomly implemented subject-specific TPACK-modules (duration: three weeks), in which pre-service teachers were taught in using technology for subject-matter teaching, whereas the control condition attended the regular courses without the TPACK-module. We found that pre-service teachers in the courses with the TPACK-modules acquired more TPACK than those in the control courses without the TPACK-modules. Significant effects were also obtained for pre-service teachers' technology-related self-efficacy and their perceived support for technology integration. The effectiveness of the TPACK-modules could be explained by the obtained support for technology integration. The findings highlight the central need of adequate support for pre-service teachers’ development of technology-related professional knowledge and motivation in teacher education programs.
•We developed a subject-specific intervention to foster pre-service teachers' TPACK.•The intervention was based on evidence-based practices of teacher education.•Effects were tested in a cluster randomized study in 5 subjects across three weeks.•TPACK was measured by test-based instruments.•Effects were obtained for TPACK, self-efficacy, and subjective support.
Cells maintain integrity despite changes in their mechanical properties elicited during growth and environmental stress. How cells sense their physical state and compensate for cell-wall damage is ...poorly understood, particularly in plants. Here we report that FERONIA (FER), a plasma-membrane-localized receptor kinase from Arabidopsis, is necessary for the recovery of root growth after exposure to high salinity, a widespread soil stress. The extracellular domain of FER displays tandem regions of homology with malectin, an animal protein known to bind di-glucose in vitro and important for protein quality control in the endoplasmic reticulum. The presence of malectin-like domains in FER and related receptor kinases has led to widespread speculation that they interact with cell-wall polysaccharides and can potentially serve a wall-sensing function. Results reported here show that salinity causes softening of the cell wall and that FER is necessary to sense these defects. When this function is disrupted in the fer mutant, root cells explode dramatically during growth recovery. Similar defects are observed in the mur1 mutant, which disrupts pectin cross-linking. Furthermore, fer cell-wall integrity defects can be rescued by treatment with calcium and borate, which also facilitate pectin cross-linking. Sensing of these salinity-induced wall defects might therefore be a direct consequence of physical interaction between the extracellular domain of FER and pectin. FER-dependent signaling elicits cell-specific calcium transients that maintain cell-wall integrity during salt stress. These results reveal a novel extracellular toxicity of salinity, and identify FER as a sensor of damage to the pectin-associated wall.
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•FER is necessary to maintain cell-wall integrity during the salt-stress response•Pectin cross-linking protects cell walls against damage induced by salinity•The extracellular domain of FER interacts directly with pectin•FER induces cell-specific Ca2+ transients that maintain cell-wall integrity
For plant cells, growth requires maintenance of cell-wall integrity. Feng et al. show that salinity weakens the cell wall, which triggers FER-mediated calcium signaling to prevent root cells from bursting during growth under salt stress. The extracellular domain of FER physically interacts with pectin, indicating a potential sensing mechanism.
Striatal dopamine drives associative learning by acting as a teaching signal. Much work has focused on simple learning paradigms, including Pavlovian and instrumental learning. However, higher ...cognition requires that animals generate internal concepts of their environment, where sensory stimuli, actions and outcomes become flexibly associated. Here, we performed fiber photometry dopamine measurements across the striatum of male mice as they learned cue-action-outcome associations based on implicit and changing task rules. Reinforcement learning models of the behavioral and dopamine data showed that rule changes lead to adjustments of learned cue-action-outcome associations. After rule changes, mice discarded learned associations and reset outcome expectations. Cue- and outcome-triggered dopamine signals became uncoupled and dependent on the adopted behavioral strategy. As mice learned the new association, coupling between cue- and outcome-triggered dopamine signals and task performance re-emerged. Our results suggest that dopaminergic reward prediction errors reflect an agent's perceived locus of control.
Sudden infant death syndrome (SIDS) is a leading cause of postneonatal mortality. Genetic heart diseases (GHDs) underlie some cases of SIDS.
This study aimed to determine the spectrum and prevalence ...of GHD-associated mutations as a potential monogenic basis for SIDS.
A cohort of 419 unrelated SIDS cases (257 male; average age 2.7 ± 1.9 months) underwent whole exome sequencing and a targeted analysis of 90 GHD-susceptibility genes. The yield of “potentially informative,” ultra-rare variants (minor allele frequency <0.00005) in GHD-associated genes was assessed.
Overall, 53 of 419 (12.6%) SIDS cases had ≥1 “potentially informative,” GHD-associated variant. The yield was 14.9% (21 of 141) for mixed-European ancestry cases and 11.5% (32 of 278) for European ancestry SIDS cases. Infants older than 4 months were more likely to host a “potentially informative” GHD-associated variant. There was significant overrepresentation of ultra-rare nonsynonymous variants in European SIDS cases (18 of 278 6.5%) versus European control subjects (30 of 973 3.1%; p = 0.013) when combining all 4 major cardiac channelopathy genes (KCNQ1, KCNH2, SCN5A, and RYR2). According to the American College of Medical Genetics guidelines, only 18 of 419 (4.3%) SIDS cases hosted a “pathogenic” or “likely pathogenic” variant.
Less than 15% of more than 400 SIDS cases had a “potentially informative” variant in a GHD-susceptibility gene, predominantly in the 4- to 12-month age group. Only 4.3% of cases possessed immediately clinically actionable variants. Consistent with previous studies, ultra-rare, nonsynonymous variants within the major cardiac channelopathy-associated genes were overrepresented in SIDS cases in infants of European ethnicity. These findings have major implications for the investigation of SIDS cases and families.
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Agrostemma githago L. (corn cockle) is an herbaceous plant mainly growing in Europe. The seeds of the corn cockle are toxic and poisonings were widespread in the past by consuming contaminated flour. ...The toxic principle of Agrostemma seeds was attributed to triterpenoid secondary metabolites. Indeed, this is in part true. However Agrostemma githago L. is also a producer of ribosome-inactivating proteins (RIPs). RIPs are N-glycosylases that inactivate the ribosomal RNA, a process leading to an irreversible inhibition of protein synthesis and subsequent cell death. A widely known RIP is ricin from Ricinus communis L., which was used as a bioweapon in the past. In this study we isolated agrostin, a 27 kDa RIP from the seeds of Agrostemma githago L., and determined its full sequence. The toxicity of native agrostin was investigated by impedance-based live cell imaging. By RNAseq we identified 7 additional RIPs (agrostins) in the transcriptome of the corn cockle. Agrostin was recombinantly expressed in E. coli and characterized by MALDI-TOF-MS and adenine releasing assay. This study provides for the first time a comprehensive analysis of ribosome-inactivating proteins in the corn cockle and complements the current knowledge about the toxic principles of the plant.
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