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51.
Michal Tabach Esther Levenson Ruthi Barkai Pessia Tsamir Dina Tirosh Tommy Dreyfus 《Journal of Mathematics Teacher Education》2011,14(6):465-481
In light of recent reform recommendations, teachers are expected to turn proofs and proving into an ongoing component of their
classroom practice. Two questions emerging from this requirement are: Is the mathematical knowledge of high school teachers
sufficient to prove various kinds of statements? Does teachers’ knowledge allow them to determine the validity of an argument
made by their students? The results of this study, in which 50 secondary school teachers participated, point to a positive
answer to the first question in the framework of elementary number theory (ENT). However, the picture is more complex with
respect to the second one. Results indicated that some teachers may over-value the generality of symbolic mode of representation
and under-value the generality of verbal ones. Possibly, the verbal representation of an argument is less transparent and
more difficult to understand. 相似文献
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Synnøve Iversen Ann‐Mari Knivsberg Bjørn Ellertsen Magne Nødland Tommy Både Larsen 《Emotional and Behavioural Difficulties》2013,18(3):169-185
Incidence, severity and types of motor difficulties in children with severe behavioural and emotional problems were evaluated. A group of 6‐year‐olds (n = 29) with such problems and controls (n = 29) were compared on the Movement Assessment Battery for Children (M‐ABC). The groups were compared on total scores as well as manual dexterity, ball skills and balance. Individual M‐ABC profiles were compared with Teacher's Report Form profiles. It was found that 62.1% in the high‐risk group and 20.7% in the control group showed motor coordination difficulties. In the high‐risk group 55.2% fulfilled the criteria of the DSM‐IV for developmental coordination disorder, compared to 3.4% controls. The high‐risk group showed significant difficulties within all sub‐areas of the M‐ABC. There was a significant relationship between attention problems and manual dexterity difficulties. The combination of problems identified makes these children vulnerable with regard to school inclusion and in need of proper assessment and intervention. 相似文献
54.
The aim of this study was to examine the effect of leg muscle fatigue on the kinetics and kinematics of the instep football kick. Fatigue was induced by repeated, loaded knee extension (40% body weight) and flexion (50% body weight) motions on a weight-training machine until exhaustion. The kicking motions of seven male players were captured three-dimensionally at 500 Hz before and immediately after the fatigue protocol. The significantly slower ball velocity observed in the fatigue condition was due to both reduced lower leg swing speed and poorer ball contact. The reduced leg swing speed, represented by a slower toe linear velocity immediately before ball impact and slower peak lower leg angular velocity, was most likely due to a significantly reduced resultant joint moment and motion-dependent interactive moment during kicking. These results suggest that the specific muscle fatigue induced in the present study not only diminished the ability to generate force, but also disturbed the effective action of the interactive moment leading to poorer inter-segmental coordination during kicking. Moreover, fatigue obscured the eccentric action of the knee flexors immediately before ball impact. This might increase the susceptibility to injury. 相似文献
55.
Tommy MacKay 《Educational Psychology in Practice》2002,18(3):245-253
The present paper is based on an invited address to the Division of Educational and Child Psychology. It outlines the opportunity for a future in which educational psychology occupies a position of central importance in society's affairs. It is a future that must embrace a wider role than special educational needs, and in which research must be a core function. Most importantly, it is a future that the profession itself must create. 相似文献
56.
Linear programming problems were presented, in a predominantly visual setting, to high school students who were not acquainted with any specific methods for solving such problems. The strategies developed by the students for coping with these problems were identified and classified. Visual strategies were developed more frequently than either algebraic or mixed ones. In many cases, these visual strategies were unsophisticated. Providing the students with a visual solution tool (a level curve of the target function) did not lead to significant changes. 相似文献
57.
Richard Haugen Thorleif Lund Yngvar Ommundsen 《Scandinavian Journal of Educational Research》2013,57(2):171-185
The purpose of the study was to explore the relationship between attribution and selected personality dispositions, as well as self‐serving attribution. Four hypotheses were formulated: (1) Attributions for positive events correlate differently with the five personality dispositions than attributions for negative events, (2) factor analysis and cluster analysis of attributions for positive and negative events and the five personality dispositions will generate a general bipolar expectancy factor, (3) self‐serving attributions will dominate irrespective of subcultural context, and (4) the dominance of self‐serving attributions will be stronger in an individualistic‐oriented context than in a collectivistic‐oriented context. One‐hundred‐and‐fifty students, selected from two educational contexts (one individualistic‐oriented and one collectivistic‐oriented), were scored on attributions for positive and negative events as well as on the five personality dispositions on the basis of an inventory. All four hypotheses were supported. Educational implications are discussed. 相似文献
58.
Much of the training of competitive telemark skiers is performed as dry-land exercises. The specificity of these exercises is important for optimizing the training effect. Our aim here was to study the activation of the knee extensor musculature and knee angular displacement during competitive telemark skiing and during dry-land strength training exercises to determine the specificity of the latter. Specificity was analysed with respect to angular amplitude, angular velocity, muscle action and electromyographic (EMG) activity. Five male telemark skiers of national and international standard volunteered to participate in the study, which consisted of two parts: (1) skiing a telemark ski course and (2) specific dry-land strength training exercises for telemark skiing (telemark jumps and barbell squats). The angular displacement of the right knee joint was recorded with an electrogoniometer. A tape pressure sensor was used to measure pressure between the sole of the foot and the bottom of the right ski boot. Electromyographic activity in the right vastus lateralis was recorded with surface electrodes. The EMG activity recorded during maximum countermovement jumps was used to normalize the EMG activity during telemark skiing, telemark jumps and barbell squats. The results showed that knee angular displacement during telemark skiing and dry-land telemark jumps had four distinct phases: a flexion (F1) and extension (E1) phase during the thrust phase of the outside ski/leg in the turn/jump and a flexion (F2) and extension (E2) phase when the leg was on the inside of the turn/jump. The vastus lateralis muscle was activated during F1 and E1 in the thrust phase during telemark skiing and telemark jumps. The overall net knee angular amplitude was significantly greater (P<0.05) for telemark jumps than for telemark skiing. Barbell squats showed a knee angular amplitude significantly greater than that in telemark skiing (P<0.05). The mean knee angular velocity of the F1 and E1 phases during telemark skiing was about 0.47 rad?·?s?1; during barbell squats, it was about 1.22 rad?·?s?1. The angular velocity during telemark jumps was 2.34 and 1.59 rad?·?s?1 in the F1 and E1 phase, respectively. The normalized activation level of the EMG bursts during telemark skiing, telemark jumps and barbell squats was 70–80%. In conclusion, the muscle action and level of activation in the vastus lateralis during the F1 and E1 phases were similar during telemark skiing and dry-land exercises. However, the dry-land exercises showed a larger knee extension and flexion amplitude and angular velocity compared with telemark skiing. It appears that an adjustment of knee angular velocity during barbell squats and an adjustment of knee angle amplitude during both telemark jumps and barbell squats will improve specificity during training. 相似文献
59.
Local research units, this article argues, play a very important role for the scientific field they belong to, for example by mobilizing financial support, offering job opportunities, attracting talented recruits, and providing adequate training. Little is known, however, about such units, at least in the fields under study here, i.e., studies of innovation, entrepreneurship and related phenomena. This article focuses - with the help of a survey of 136 research units worldwide supplemented by a number of case-studies - on the factors that influence the extent to which local mobilization efforts succeed. The research shows that universities provide the most fertile grounds for such research units, and that external support and support from the leadership of the university are important factors behind their establishment. In the longer term, however, attracting core (basic) finance is essential for the unit's ability to maintain cognitive control of its research program. Units that develop their own Master and PhD programs appear more likely than others to achieve these aims. 相似文献
60.
This case study deals with a solitary learner’s process of mathematical justification during her investigation of bifurcation
points in dynamic systems. Her motivation to justify the bifurcation points drove the learning process. Methodologically,
our analysis used the nested epistemic actions model for abstraction in context. In previous work, we have shown that the
learner’s attempts at justification gave rise to several processes of knowledge construction, which develop in parallel and
interact. In this paper, we analyze the interaction pattern of combining constructions and show that combining constructions
indicate an enlightenment of the learner. This adds an analytic dimension to the nested epistemic actions model of abstraction
in context. 相似文献