Arranging program statements for locality on the basis of neighbourhood preferences

AbstractThe gradual property of computer programs, that their successive operations preferably access data from the same memory block, is called locality. The paper deals with locality optimization, more specifically with the sequencing aspect that N operations are to be brought into sequence such that locality is maximized. We assume to be given a matrix D = [Dij] of neighbourhood preferences, where entry Dij is the smaller the higher the expected gain in locality when arranging operations oi and oj closely. The gain is supposed to have been estimated from so far accumulated but still incomplete knowledge of an overall locality optimization process. Our task consists in finding a sequencing function T : {o1 … oN} → [l … N] ⊆ R that assigns to each operation a real time at which it will be approximately carried out. The motivation for T mapping into reals instead of integers is to transfer more knowledge on the certainty of operation ordering decisions into the next step of the overall locality optimization process. The goal for T consists in minimizing an objective function that was empirically designed to approximately quantify the intuitive meaning of the degree of locality. In addition, T has to spread the values T(oi) quite evenly over the interval [l … N]. We suggest a heuristic algorithm that approximately solves the problem, and report on experiments with the algorithm and several variants of it. Briefly, the algorithm starts with a random sequencing that is iteratively improved, by alternatingly moving each T(oi) in the direction of the value that minimizes the objective function for fixed T(oj)(j ≠ i), and spreading the T(oi) over [l … N]. Experimental results indicate that our algorithm is efficient and reasonably accurate

Der Einsatz von Lernstrategien in einer konkreten Lernsituation bei Schülern unterschiedlicher Jahrgangsstufen

Der Beitrag ist darauf ausgelegt, jeweils einen Ansatzpunkt zur Optimierung von Erziehungsanstrengungen zu benennen und die Wirksamkeit der vorgeschlagenen Maßnahmen empirisch zu belegen ... . Die Autoren untersuchen die Verwendung selbstregulatorischer Lernstrategien in unterschiedlichen Jahrgangsstufen. Dabei legen sie ihren Schwerpunkt zunächst auf die Analyse der Veränderung des Lernstrategieeinsatzes im Zeitverlauf und die Beziehungen zwischen Lernerfolg und Strategieeinsatz. (DIPF/Orig.

Self-regulated learning as self-regulation of learning strategies - A training experiment on leaming from texts

Insgesamt 69 Berufstätige nahmen an vier Tagen an einem aus vier Modulen bestehenden computer-basierten Training zum selbstregulierten Lernen aus Texten teil. Gegenstand der Trainingsmodule waren Lernstrategien zur Erfüllung der vier Klauer\u27schen Lehrfunktionen Motivation, Information, Informationsverarbeitung sowie Steuerung und Kontrolle. Je nach Zugehörigkeit zur experimentell variierten Trainingsbedingung erhielten die Versuchspersonen bei jedem Modul (1) kein spezifisches Training, (2) nur ein Training der Lernstrategie oder (3) ein kombiniertes Training der Lernstrategie und darauf bezogener Selbstregulation. Zur Erfassung der anfänglichen Lesekompetenz bearbeiteten die Versuchspersonen vor Beginn des Trainings einen Lehrtext sowie einen zugehörigen lehrzielorientierten Test. Nach jedem Trainingsmodul bearbeiteten sie zur Anwendung der Trainingsinhalte ebenfalls einen Lehrtext, und es wurde ebenfalls anhand eines lehrzielorientierten Tests erhoben, wie viel Wissen sie aus der Bearbeitung des Textes gewonnen hatten. Die Teilnehmer des kombinierten Trainings schnitten im Vortest-Nachtest-Vergleich deutlich besser ab als die Teilnehmer des Lernstrategietrainings und als die Teilnehmer der Kontrollbedingung ohne Training. Die im Rahmen dieses Trainingsansatzes erzielten Ergebnisse entsprechen aktuellen Theorien des Trainings von Lernstrategien, die davon ausgehen, dass es sinnvoll ist, neben der Vermittlung von Wissen über einzelne Lernstrategien auch den zielführenden Einsatz der jeweiligen Lernstrategie mit zu trainieren. (ZPID

Science text comprehension: Drawing, main idea selection, and summarizing as learning strategies

The purpose of two experiments was to contrast instructions to generate drawings with two text-focused strategies—main idea selection (Exp. 1) and summarization (Exp. 2)— and to examine whether these strategies could help students learn from a chemistry science text. Both experiments followed a 2 × 2 design, with drawing strategy instructions (yes vs. no) and main idea/summarization strategy instructions (yes vs. no) as experimental factors. The main dependent variable was science text comprehension, measured by a multiple-select test and a transfer test. Participants were 90 (Exp. 1) and 71 (Exp. 2) students (grade 10). The results of both experiments showed positive effects of the drawing strategy instructions and negative effects of the text-focused strategy instructions without interactions. These results are consistent with the mental model approach to comprehension, showing advantages of drawing activity in fostering science text comprehension

Improving students’ science text comprehension through metacognitive self-regulation when applying learning strategies

In three experiments, students were trained to use strategies for learning from scientific texts: text highlighting (Experiment 1), knowledge mapping (Experiment 2), and visualizing (Experiment 3). Each experiment compared a control condition, cognitive strategy training, and a combined cognitive strategy plus metacognitive selfregulation training with a specific focus on the quality of cognitive strategy application. After the training, students applied the learning strategies as they studied scientific texts. Across experiments, the results indicated that the self-regulation component of the training helped the students to overcome the lack of efficacy of the cognitive strategy only training when it was not effective by itself: The highlightingonly group was outperformed by the control group (d = −1.25), but the combined highlighting-plus-self-regulation training reduced this negative effect (d = −0.21). The mapping-only group performed as well as the control group (d = −0.12), but the combined mapping-plus-self-regulation group outperformed the control group (d =  0.76). The visualizing-only group outperformed the control group (d = 0.72) as did the combined visualizing-plus-self-regulation group (d = 0.78). Results suggest that cognitive learning strategies differ in their potential to induce deep versus surface processing of text contents. In addition, the metacognitive self-regulation component of the training enhanced students’ performance when the cognitive strategy training was not effective by itself

An Imagination Effect in Learning From Scientific Text

Asking students to imagine the spatial arrangement of the elements in a scientific text constitutes a learning strategy intended to foster deep processing of the instructional material. Two experiments investigated the effects of mental imagery prompts on learning from scientific text. Students read a computer-based text on the human respiratory system (control group), read while being asked to form an image corresponding to each of 9 paragraphs (imagery group), or read while being asked to form an image and with seeing an onscreen drawing before each paragraph (picture- before-imagery group) or after each paragraph (picture-after-imagery group). Imagery prompts facilitated transfer and retention performance compared to a control group on an immediate test (Experiment 1: d = 1.30 on transfer, d = 0.74 on retention) and on a delayed test (Experiment 2: d = 0.86 on transfer, d = 0.98 on retention), but the added drawings had no additional effect. The findings support the imagination principle, which states that people learn more deeply when prompted to form images depicting the spatial arrangement of what they are reading

Drawing instructions, strategic knowledge, strategy-based motivation, and students’ use of drawings

Although self-generated drawing is a powerful strategy in the domain of geometry, students lack spontaneous use of the drawing strategy. In the current study, we investigated instructional, cognitive, and motivational predictors of students’ drawing use. We first assessed strategic knowledge about drawing and strategy-based motivation in 132 students in Grades 9 and 10. Then, students were randomly assigned to solve geometry modelling problems either with or without drawing instructions. Students with drawing instructions constructed more drawings than students without drawing instructions. Strategic knowledge about drawing, self-efficacy expectations, and perceived costs predicted drawing use while intramathematical abilities were controlled for. Utility value did not predict drawing use in the current study.The present study was funded by the German Research Foundation [Deutsche Forschungsgemeinschaft, grant number SSCHU 2629/3-1] and the Swiss National Science Foundation [Schweitzer Nationalfond, grant number 100019E-164816/1]

Learning with summaries: Effects of representation mode and type of learning activity on comprehension and transfer

The purpose of the experiment was to examine whether students better understand a science text when they are asked to self-generate summaries or to study predefined summaries. Furthermore, we tested the effects of verbal and pictorial summaries. The experiment followed a 2 × 2 design with representation mode (verbal vs. pictorial) and learning activity (self-generating vs. studying) as experimental factors. The main dependent variables were learning performance, measured by a comprehension and a transfer test, and strategy use, measured by self-report scales. Seventy-one students (Grade 10) participated in the study. The results showed that studying predefined summaries in a pictorial representation mode facilitated deep understanding. Furthermore, mediation analysis showed that the effect of representational mode was mediated by students' spatial representations of learning content. The effect of spatial representations was in turn facilitated by mental imagery activities

Make a drawing. Effects of strategic knowledge, drawing accuracy, and type of drawing on students’ mathematical modelling performance

Drawing strategies are widely used as a powerful tool for promoting students’ learning and problem solving. In this article, we report the results of an inferential mediation analysis that was applied to investigate the roles that strategic knowledge about drawing and the accuracy of different types of drawings play in mathematical modelling performance. Sixty-one students were asked to create a drawing of the situation described in a task (situational drawing) and a drawing of the mathematical model described in the task (mathematical drawing) before solving modelling problems. A path analysis showed that strategic knowledge about drawing was positively related to students’ modelling performance. This relation was mediated by the type and accuracy of the drawings that were generated. The accuracy of situational drawing was related only indirectly to performance. The accuracy of mathematical drawings, however, was strongly related to students’ performance. We complemented the quantitative approach with a qualitative in-depth analysis of students’ drawings in order to explain the relations found in our study. Implications for teaching practices and future research are discussed

Application of lower Punch Vibration to improve the mechanical Stability of Tablets

A sufficient mechanical stability of tablets to be compacted prevents problems during tableting (e.g. sticking, capping, lamination) and is crucial with regard to further processing steps such as coating or packaging. Often, an improvement of the mechanical stability is only achievable by an adaption of the production settings (die disk speed) or an alteration of the powder blend composition. In the present study, a novel lower punch vibration device was developed and implemented on a rotary tablet press to improve the mechanical stability of the resulting tablets without changing the production conditions or the powder formulation. Various types of microcrystalline cellulose with different physical properties were selected. The powders were investigated concerning their powder flow, density, particle morphology and surface area and the tablets concerning their weight, tensile strength, and capping index. The results showed that externally applied lower punch vibration improved the mechanical stability of the investigated tablets beyond the adaption of the production settingss and the physical properties of the powder blend