Search

Computational Thinking (CT) is regarded as a crucial competency for all children in the 21st century. There are misconceptions about CT which confounds CT skills with programming skills. However, CT skills and programming skills are not the same. CT is a broader skillset of cognitive thinking that is integral to complex problem solving. Teaching and assessing CT should not only focus on computer programming. In this project, a new design-based learning (DBL) approach was proposed to improve elementary school students' CT. This approach not only included programming skills, but also integrated CT practices with authentic real-life contexts. Corresponding to recent conceptions of CT, we also assessed CT in a more comprehensive manner. A quasi-experiment study was carried out to assess how the intervention was associated with students' self-perceived CT skills using both quantitative and qualitative methods. In the treatment group, twenty-three fourth graders engaged in three curriculum units to create artifacts that solve specific real-world problems using LabPlus electronic kits and Scratch programming software. The control group took a traditional computer science class. Results revealed that students' self-perceived CT skills increased to a greater extent in the treatment group compared to the control group. In addition, we observed and interviewed three student cases in the treatment group to understand the potential learning effects of our new DBL approach. This study contributes to research in CT instruction, its application in STEM education in particular, and how it can be used in elementary level education in general.

Despite the continuous emphasis on emotion in multimedia learning, it was still unclear how pedagogical agent emotional cues might affect learning. In the present study, a between-subjects experiment was performed to examine the effects of a pedagogical agent with dual-channel emotional cues on learners' emotions, cognitive load, and knowledge transfer performance. Participants from a central Chinese university (age mean = 21.26, N = 66) were randomly divided into three groups. These groups received instructions from an affective pedagogical agent, a neutral pedagogical agent, or a neutral voice narration without pedagogical agent embodiment. Results showed that learners assigned the affective pedagogical agent reported a significantly higher emotional level than learners assigned the neutral pedagogical agent. Learners' perceived task difficulty was not significantly different among groups while instructional efficiency was significantly higher for learners with the affective pedagogical agent. Moreover, learners assigned to the affective pedagogical agent performed significantly better on the knowledge transfer test than those assigned the neutral pedagogical agent or the neutral voice.

Understanding the role of teaching presence in students' learning can help improve online teaching. This study explored the effects of online teaching presence on students' cognitive conflict and engagement by analyzing three rounds of a course taught with different levels of teaching presence. The participants were 132 students enrolled across the three rounds. Content and lag sequential analysis were used to explore the effects of teaching presence on students' cognitive conflict and learning engagement. The results show that design and facilitation can engage students in reflection and involve them in cognitive conflicts and cognitive engagement (p < 0.001). Moreover, timely facilitation and direct instruction had no significant effect on students' responses to cognitive conflict. These results illuminate the impact of teaching presence on students' learning engagement through cognitive conflict and provide instructors with practical guidance for online teaching.

Differences in how students and teachers understand online teaching presence play a key role in teaching design. To explore how students and teachers perceive teaching presence, this study surveyed 1,041 students and 18 teachers who participated in an online course at a Chinese university. The analysis found students' perceived teaching presence was significantly lower than the teachers', particularly in terms of facilitating discourse (p < 0.001). Regarding the perceived importance of the five dimensions of teaching presence (Wang et al., 2019), students perceived facilitating discourse to be more important than direct instruction, while the opposite was found to be true for teachers. The divergence creates a challenge for teachers in engaging students in learning. The results indicate that teachers could pay more attention to the following dimensions to improve students' learning experience: making macro-level comments on courses, designing instructional methods, providing formative feedback for homework and discussions, and making full use of technological tools in teaching.

This study investigated whether video lectures instructed by a heightened level of expressiveness instructor were better than those instructed by a conventional level of expressiveness instructor or audio-only in promoting students' online learning, and what kind of effects do instructor's facial expressions have on students' learning. Three different types of video lectures (one with a heightened level of expressiveness instructor, one with a conventional level of expressiveness instructor and one with the instructor' audio only) were used to study the effects of instructor's facial expressions. Sixty-nine participants from Chinese Normal University were selected to learn with these video lectures. Results of this study indicated that video lectures with a heightened level of expressiveness instructor were better than those with a conventional level of expressiveness instructor and audio-only ones with regard to improving students' arousal level and learning satisfaction. Instructor's facial expressions had no significant influence on participants' short-term recall (p = 0.90), while instructor's facial expressions did influence students' medium-term recall (p = 0.03). Instructor's facial expressions played a key role in students' online learning.

• High-order numerical scheme for the solution of the dissolution and Stefan problems. • Accurate computation of surface shear stress and solute concentration gradients at solid-liquid interface. • Numerical exploration and investigation of the onset of surface patterning. • Immersed Boundary Smooth Extension method for moving interface problems. The dissolution of solids has created spectacular geomorphologies ranging from centimeter-scale cave scallops to the kilometer-scale "stone forests" of China and Madagascar. Mathematically, dissolution processes are modeled by a Stefan problem, which describes how the motion of a phase-separating interface depends on local concentration gradients, coupled to a fluid flow. Simulating these problems is challenging, requiring the evolution of a free interface whose motion depends on the normal derivatives of an external field in an ever-changing domain. Moreover, density differences created in the fluid domain induce self-generated convecting flows that further complicate the numerical study of dissolution processes. In this contribution, we present a numerical method for the simulation of the Stefan problem coupled to a fluid flow. The scheme uses the Immersed Boundary Smooth Extension method to solve the bulk advection-diffusion and fluid equations in the complex, evolving geometry, coupled to a θ - L scheme that provides stable evolution of the boundary. We demonstrate 3rd-order temporal and pointwise spatial convergence of the scheme for the classical Stefan problem, and 2nd-order temporal and pointwise spatial convergence when coupled to flow. Examples of dissolution of solids that result in high-Rayleigh number convection are numerically studied, and qualitatively reproduce the complex morphologies observed in recent experiments. [ABSTRACT FROM AUTHOR]