Aluminum (1050) was deformed by plane strain compression (PSC) up to 75% reduction. The total deformation conditions include four temperatures (from 150oC to 300oC) and two strain rates (5¡Ñ10-2s-1 and 5¡Ñ10-4s-1). After the deformation, the specimens were examined by TEM for observing the morphology of the microstructures and measuring various parameters, which includes the sizes and aspect ratios of dislocation cells, as well as the distribution of misorientation angles for dislocation walls.

The current study investigates the effects of preparing learners for an online debate through a worked example in terms of student perception, participation, level of cognitive skill, and electronic interaction patterns. There has been a change in the focus of distance learning research from comparative media studies to the means to improve the quality of distance education. One of the key elements in this changing impetus are strategies to promote interaction such as the introduction of structure or scaffolding argumentation (McIsaac & Blocher, 1998). One such strategy is the online debate in which students are organized into teams to take a position on an issue and argue on its behalf (Jeong, 2004). The debate is constrained through the addition of rules and specific message headers. Well-designed quality interaction holds the potential to create more satisfied learners and higher quality learning outcomes (Muirhead, 2002), but in the absence of quality, interaction has been found to actually lead to a decrease in satisfaction, participation, and performance (Joung & Keller, 2004; Kreijns, Kirschner, & Jochems, 2002). One way to ensure quality within interactive exercises such as online debate is to prepare students through a worked example. A worked example models an expert’s work and demonstrates desired behaviors for the learner to study (Atkinson, Derry, Renkl, & Wortham, 2000). Students were randomly assigned to teams to participate in an online debate with half being given access to a worked example before participating. In order to examine the effects of the worked example on students’ perceived satisfaction and level of preparedness, a survey was administered at various points throughout the semester. Additionally, debate transcripts were analyzed for participation, cognitive skill, and interaction patterns. The results demonstrate that students prepared through a worked example participated more frequently, wrote more words or phrases that encouraged the participation of others, and used higher-order thinking skills. The conclusion was that worked examples can be used to model behaviors for students to emulate. The implication being that instructors should consider providing worked examples before engaging students in online debate and future research should examine the efficacy of a worked example in preparing learners for other types of interactive activities.

This study investigated the usefulness of providing successful and unsuccessful example solutions in enhancing students' technological problem-solving efficiency. Prior research exploring worked example solutions indicated improved problem-solving efficiency when solutions were structured in a fashion that decreased the amount of extraneous cognitive load and increased the amount of germane cognitive load as specified by cognitive load theory. Fifty-one 7th and 8th grade students enrolled in technology education courses were selected from one school in the southwest region of Virginia. Participants completed three technological problem-solving tasks that included elevated load, cantilevered weight, and energy absorption using supply kits containing simple modeling materials. Problem-solving efficiency was determined by combining the amount of elapsed time across all three tasks. A 3 x 3 mixed factorial ANOVA was used to analyze the data. Data analysis revealed trends similar to worked example research in mathematics and science, but no significant difference among the three groups was found in this study. / Ph. D.

Educators in the current era face more pressure to meet learners' growing digital age learning needs, which may require fostering more vital computational thinking skills. To ensure the desired learning outcomes are attained, it is critical to know how to provide the appropriate type of guidance and assistance. The findings of this research may be significant to computer science instructors and instructional designers interested in fostering computational thinking skills and improving programming skills by designing effective worked examples. Following the integrative review methodology, the study examined the current literature on worked examples in a programming setting to determine the compelling designs of worked examples. In addition, this study examined the most employed instructional design principles in developing effective worked examples and explored factors and circumstances that may have impacted the effectiveness of those designs. This study's findings indicated several successful designs of worked examples to promote computational thinking skills in programming problems / Doctor of Philosophy / Educators focus on fulfilling learners' expanding digital age learning requirements, which may require developing more critical computational thinking skills. It is vital to understand how to give appropriate guidance and support to achieve the intended learning results in programming courses. The outcomes of this study may be helpful to computer science educators and instructional designers who aim to support learners in gaining more advanced computational thinking skills. The study used the integrative review approach to investigate the current literature on worked examples in a programming context to discover the compelling designs of worked examples. The study provides information about the factors that may affect the design in addition to discuss several instructional design principles in regard to worked examples. The outcomes of this study showed numerous successful designs of worked examples that are helping in enhancing computational thinking skills in programming tasks.

Empirical studies have shown that learning from worked examples is an effective learning strategy. A worked example provides step-by-step explanations of how a problem is solved. Many studies have compared learning from examples to unsupported problem solving, and suggested presenting worked examples to students in the initial stages of learning, followed by problem solving once students have acquired enough knowledge. Recently, researchers have started comparing learning from examples to supported problem solving in Intelligent Tutoring Systems (ITSs). ITSs provide multiple levels of assistance to students, adaptive feedback being one of them. The goal of this research is to investigate using examples in constraint-based tutors by adding examples into SQL-Tutor. SQL-Tutor is a constraint-based tutor that teaches the Structured Query Language (SQL). Students with different prior knowledge benefit differently from studying examples; thus, another goal of the research is to propose an adaptive model that considers the student’s prior knowledge for providing worked examples. Evaluation of this research produced promising results. First, a fixed sequence of alternating examples and problems was compared with problems only and examples only. The result shows that alternating examples and problems is superior to the other two conditions. Then, a study was conducted, in which a fixed sequence of alternating worked examples and tutored problem solving is compared with a strategy that adapts the assistance level to students’ needs. The adaptive strategy determines the type of the task (a worked example, a faded example or a problem to be solved) based on how much assistance the student received in the previous problem. The results show that students in the adaptive condition learnt significantly more than their peers who were presented with the fixed sequence of worked examples and problem solving. The final study employed eye tracking and demonstrated that novices and advanced students study SQL examples differently. Such information can be used to provide proactive rather than reactive feedback messages to students’ actions.

Researchers and instructors have only recently embraced the role of errors as vehicles for learning in the algebra classroom. Studying a mixture of correct and incorrect worked examples has been shown to be beneficial relative to correct worked examples alone. This study examines the effectiveness of having students generate, or anticipate, errors another student might make. Five Algebra 1 sections at a suburban mid-Atlantic public high school participated amid an early equation-solving unit. During teacher-led instruction, all five sections examined 2-3 correct worked examples. The final example varied across conditions. One section received an additional correct worked example. Two sections examined an incorrect worked example. The remaining two sections engaged in an error anticipation exercise where the teacher wrote an equation on the board and asked the students to predict errors another student might make in solving. The study measured conceptual and procedural knowledge, encoding ability, and student-generated errors. Although no meaningful significant differences were found, students in the error anticipation condition saw no difference in performance in conceptual and procedural items versus those who examined incorrect worked examples. Analysis that combined the error anticipation and incorrect worked examples conditions showed that those students trended toward outperforming those who examined correct examples only on procedural items. These results support further examination of error anticipation as a worthwhile instructional activity. / Math & Science Education

The present study combined subgoal learning and self-explanation frameworks to improve problem solving performance. Subgoal learning has been used to promote retention and transfer in procedural domains, such as programming. The primary method for learning subgoals, however, has been through passive learning methods, and passive learning methods are typically less effective than constructive learning methods. To promote constructive methods of learning subgoals, a subgoal learning framework was used to guide self-explanation. Self-explanation is an effective method for engaging learners to make sense of new information based on prior knowledge and logical reasoning. Self-explanation is typically more effective when learners receive some guidance, especially if they are novices, because it helps them to focus their attention on relevant information. In the present study, only some of the constructive learning methods produced better problem solving performance than passive learning methods. Learners performed best when they learned constructively and either received hints about the subgoals of the procedure or received feedback on the self-explanations that they constructed, but not when they received both hints and feedback. When students received both types of guidance, they did not perform better than those who learned subgoals through passive learning methods. These findings suggest that constructive learning of subgoals can further improve the benefits of learning subgoals, but there is an optimal level of guidance for students engaging in constructive learning. Providing too much guidance can be as detrimental as providing too little. This nuance is important for educators who engage their students in constructive learning and self-explanation to recognize and promote the best results.

<div> <div> <div> <p>Recent research asserts that the mnemonic benefits gained from retrieval-based learning vanish for complex materials. Subsequently, it is recommended that students study worked examples when learning about complex, problem-centered tasks. The experiments that have evaluated the effectiveness of studying worked examples tend to overlook the mental processing that students engage in when completing retrieval-based learning activities. In contrast, theories of transfer-appropriate processing emphasize the importance of compatibility between the cognitive processing required by the test and the cognitive processing that is activated during learning. For learners to achieve optimal test performance, according to transfer-appropriate processing, they need to study in such a way that they are engaging in the same mental processing that will be required of them when tested. This idea was used to generate testable predictions that compete against the claim that the retrieval practice effect disappears for complex materials, and these competing predictions were evaluated in three experiments that required students to learn about the Poisson probability distribution. </p><p><br></p> <p>In Experiment 1, students learned the general procedure for how to solve these problems by either repeatedly recalling the procedural steps or by simply studying them. The retrieval practice condition produced better memory for the procedure on an immediate test compared to the study only condition. In Experiment 2, students engaged in the same learning activities as Experiment 1, but the test focused on their problem- solving ability. Students who practiced retrieval of the procedural steps experienced no benefit on the problem-solving test compared to the study only condition. In Experiment 3, students learned to solve Poisson probability problems by studying four worked examples, by studying one worked example and solving three practice problems, or by studying one worked example and solving three practice problems with feedback. Students were tested on their problem-solving ability one week later. The problem- solving learning activities outperformed the worked example condition on the final problem-solving test. Taken together, the results demonstrate a pronounced retrieval practice effect but only when the retrieval-based learning activities necessitated the same mental processing that was required during the final assessment, providing support for the transfer-appropriate processing account.</p></div></div></div>

In our research, aluminum (1050) was deformed by plane strain compression (PSC) up to 65% reduction. The total deformation conditions include four temperatures (from 150oC to 300oC) and two strain rates (5¡Ñ10-2s-1 and 5¡Ñ10-4s-1). After the deformation, the specimens were examined by TEM for observing the morphology of the microstructures and measuring various parameters, which includes the sizes and aspect ratios of dislocation cells, as well as the distribution of misorientation angles for dislocation walls. At last, the proportions of GNBs and IDBs were tried to be determined.

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