The predictive power of intuitive rules: A critical analysis of the impact of `more A–more B' and `same A–same B'     

Wim Van Dooren  Dirk De Bock  Dave Weyers  Lieven Verschaffel 《Educational Studies in Mathematics》2004,56(2-3):179-207

In the international community of mathematics and science educators the intuitive rules theory developed by the Israeli researchers Tirosh and Stavy receives much attention. According to this theory, students' responses to a variety of mathematical and scientific tasks can be explained in terms of their application of some common intuitive rules. Two major intuitive rules are manifested in comparison tasks: ‘More A—more B’ and ‘Same A—same B’. In this paper, we address two important questions for which the existing literature on intuitive rules does not provide a convincing research-based answer: (1) are the reasoning processes of students who respond in line with a given intuitive rule actually affected by that rule or by essentially other misconceptions (leading to the same answer), and (2) are individual students consistent in their choice of one of the intuitive rules when confronted with different, conceptually unrelated tasks? A test consisting of five comparison problems from different mathematical subdomains was administered collectively to 172 Flemish students from Grades 10 to 12. An analysis of students' written calculations and justifications suggested that the students were considerably less affected by the intuitive rules than their multiple-choice answers actually suggested. Instead, essentially different misconceptions and errors were found. With respect to the issue of individual consistency, we found that students who made many errors did not answer systematically in line with one of the two intuitive rules.  相似文献   

Student perceptions of privacy principles for learning analytics     

Dirk Ifenthaler  Clara Schumacher 《Educational technology research and development : ETR & D》2016,64(5):923-938

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A Simplified Estimation of Latent State—Trait Parameters     

Dirk Hagemann  David Meyerhoff 《Structural equation modeling》2013,20(4):627-650

The latent state–trait (LST) theory is an extension of the classical test theory that allows one to decompose a test score into a true trait, a true state residual, and an error component. For practical applications, the variances of these latent variables may be estimated with standard methods of structural equation modeling (SEM). These estimates allow one to decompose the coefficient of reliability into a coefficient of consistency (indicating true effects of the person) plus a coefficient of occasion specificity (indicating true effects of the situation and the person–situation interaction). One disadvantage of this approach is that the standard SEM analysis requires large sample sizes. This article aims to overcome this disadvantage by presenting a simple method that allows one to estimate the LST parameters algebraically from the observed covariance matrix. A Monte Carlo simulation suggests that the proposed method may be superior to the standard SEM analysis in small samples.  相似文献   

Viscoelasticity of blood and viscoelastic blood analogues for use in polydymethylsiloxane in vitro models of the circulatory system     

Laura Campo-Dea?o  Roel P. A. Dullens  Dirk G. A. L. Aarts  Fernando T. Pinho  Mónica S. N. Oliveira 《Biomicrofluidics》2013,7(3)

The non-Newtonian properties of blood are of great importance since they are closely related with incident cardiovascular diseases. A good understanding of the hemodynamics through the main vessels of the human circulatory system is thus fundamental in the detection and especially in the treatment of these diseases. Very often such studies take place in vitro for convenience and better flow control and these generally require blood analogue solutions that not only adequately mimic the viscoelastic properties of blood but also minimize undesirable optical distortions arising from vessel curvature that could interfere in flow visualizations or particle image velocimetry measurements. In this work, we present the viscoelastic moduli of whole human blood obtained by means of passive microrheology experiments. These results and existing shear and extensional rheological data for whole human blood in the literature enabled us to develop solutions with rheological behavior analogous to real whole blood and with a refractive index suited for PDMS (polydymethylsiloxane) micro- and milli-channels. In addition, these blood analogues can be modified in order to obtain a larger range of refractive indices from 1.38 to 1.43 to match the refractive index of several materials other than PDMS.  相似文献   

The Interaction of Functional and Dysfunctional Emotions During Balance Beam Performance     

Jorge Cottyn  Dirk De Clercq  Geert Crombez  Matthieu Lenoir 《Research quarterly for exercise and sport》2013,84(2):300-307

The interaction between functional and dysfunctional emotions, as one of the major tenets of the Individual Zones of Optimal Functioning (IZOF) model (Hanin, 2000), was studied in a sport specific setting. Fourteen female gymnasts performed three attempts of a compulsory balance beam routine at three different heights. Heart rate and self-report of functional and dysfunctional emotions were measured during each routine. These data revealed the effectiveness of inducting emotions by manipulating height. Also, performance decreased on the most challenging condition, (i.e., the first attempt on the highest height). Moderated hierarchical regression analysis revealed a significant interaction between functional and dysfunctional emotions only when the dysfunctional emotion level was low.  相似文献   

The energetics and benefit of an arm swing in submaximal and maximal vertical jump performance     

Adrian Lees  Jos Vanrenterghem  Dirk De Clercq 《Journal of sports sciences》2013,31(1):51-57

Abstract

The aims of this study were to investigate the energy build-up and dissipation mechanisms associated with using an arm swing in submaximal and maximal vertical jumping and to establish the energy benefit of this arm swing. Twenty adult males were asked to perform a series of submaximal and maximal vertical jumps while using an arm swing. Force, motion and electromyographic data were recorded during each performance and used to compute a range of kinematic and kinetic variables, including ankle, knee, hip, shoulder and elbow joint powers and work done. It was found that the energy benefit of using an arm swing appears to be closely related to the maximum kinetic energy of the arms during their downswing, and increases as jump height increases. As jump height increases, energy in the arms is built up by a greater range of motion at the shoulder and greater effort of the shoulder and elbow muscles but, as jump height approaches maximum, these sources are supplemented by energy supplied by the trunk due to its earlier extension in the movement. The kinetic energy developed by the arms is used to increase their potential energy at take-off but also to store and return energy from the lower limbs and to “pull” on the rest of the body. These latter two mechanisms become more important as jump height increases with the pull being the more important of the two. We conclude that an arm swing contributes to jump performance in submaximal as well as maximal jumping but the energy generation and dissipation sources change as performance approaches maximum.  相似文献   

The development of students’ use of additive and proportional methods along primary and secondary school     

Ceneida Fernández  Salvador Llinares  Wim Van Dooren  Dirk De Bock  Lieven Verschaffel 《European Journal of Psychology of Education - EJPE》2012,27(3):421-438

This study investigates the development of proportional and additive methods along primary and secondary school. In particular, it simultaneously investigates the use of additive methods in proportional word problems and the use of proportional methods in additive word problems. We have also studied the role played by integer and non-integer relationships between the given numbers and the nature of quantities (discrete or continuous) in the development of these phenomena. A test consisting of additive and proportional missing-value word problems was solved by 755 primary and secondary school students (from fourth to tenth grade). The findings indicate that the use of additive methods in proportional situations increased during primary school and decreased during secondary school, whereas the use of proportional methods in additive situations increased along primary and secondary school. Moreover, the presence or absence of integer ratios strongly affects this behavior, but the nature of quantities only has a small influence on the use of proportional methods.  相似文献   

The role of self- and social directed goals in a problem-based, collaborative learning context     

Dirk T. Tempelaar  Marold Wosnitza  Simone Volet  Bart Rienties  Bas Giesbers  Wim H. Gijselaers 《Higher Education》2013,66(2):253-267

Students’ learning goals demonstrate much stronger variety than traditional goal orientation models for classroom learning assume, especially when the educational context allows so. In this empirical study we will investigate the richness of students’ goal orientation in a collaborative learning context. We do so with the help of a goal setting framework that is based on a two-facet approach distinguishing multiple contents (performance, learning, well-being) and goal directions (varying degrees of self vs social direction). To investigate the role of different goal constellations, goal setting and learning performance data of first year students (n = 2,636) in a problem-based, collaborative learning program, and evaluation data of problem-based tutorial groups (#groups = 206) are combined into a multilevel model. Each tutorial group functions in two different educational settings: one directed at open-ended, group problems, the other at closed, individual problems. Educational context appears indeed to have a crucial role in the relationship between students’ goal setting at the one side, and students’ performance and group functioning on the other side.  相似文献   

A Behaviorally Oriented Study Skills Program     

Dirk C. Prather 《Journal of Experimental Education》2013,81(3):131-133

A study skills program should have low time requirements, raise the student’s GPA, and create durable behaviors. Twenty-four male sophomore cadets at the USAF Academy were placed in one of two groups by their rank-order place on a list of academically deficient students. The experimental group and the control group both received normal directive counseling. The experimental group received a behaviorally oriented study skills program requiring two hours of supervisory time and minimal behavior recording and showed a mean increase of .54 GPA points; the control group showed an increase of .02 at the end of the semester. The results indicate this program satisfied the basic requirement of study skills training.  相似文献   

Ownership concentration and innovativeness of corporate ventures     

Katrin Hussinger  Johannes M.H. Dick  Dirk Czarnitzki 《Research Policy》2018,47(2):527-541

Corporate venture investments are an established means for incumbent firms to access radical innovation. Drawing from a behavioural agency framework, we distinguish two mechanisms that govern the relationship between corporate venture investment and radical innovation, the safety net that corporate sponsors provide and control incentives. While the safety net induces a gap between the radical innovation success of corporate ventures (CVs) and ventures without a corporate sponsor, the superior radical innovation success of CVs decreases with the corporate sponsor’s incentives to control the venture. The impact of the safety net and control incentives further depends on the corporate sponsor’s position vis-à-vis her aspiration level.  相似文献