倘若她是天使

有着俊朗外貌的Tommy Shane Steinerr以纯正的乡村歌喉演唱着属于他牛仔风格的歌曲。他出道后,受到了许多前辈的关注和提携:连续11年主持乡村音乐协会年度颁奖典礼的歌星Vince Gill出人意料地为Steiner的主推曲What If She’s An Angel配唱了合     

New actions upon old objects: A new ontological perspective on functions

We argue in this paper that the systematic use of special software in instruction has a profound impact on the notion of function as an abstract entity to be constructed. We argue that through the medium of the computer, the objects in the graphical, tabular and algebraic settings can change their essence and thus become objects of a new kind we callrepresentatives. Actions on representatives which naturally arise in this framework induce an ontological shift. A taxonomy of the skills involved in the learning of the concept of function through these new ontological lenses is presented, as well as software, and problem solving tasks that embody the same ontological perspective. Within the framework of a teaching experiment, students' acquisition of many of the identified skills was investigated by means of a questionnaire and interviews during computer supported problem solving sessions. The most salient results of the study indicate that a majority of students were able (1) to cope with partial data about functions (e.g., problems of interpolation and arbitrariness), (2) to recognize invariants (i. e., properties of functions) while coordinating actions among representatives from different settings, and (3) to recognize invariants while creating and comparing different representatives from the same setting.     

Optimal presentation of graphic organizers and text: A case for large bites?

In three experiments, we investigated the optimal presentation of graphic organizers (GOs) and text by having undergraduates read a chapter-length text in its entirety, a few pages at a time, or a few sentences at a time, before or after viewing seven GOs in their entirety (large bites), one at a time (small bites), or one cell at a time (animated). Large bites were better than small bites for learning concept relations and applying that knowledge, and for recalling macropropositions when the GOs were presented before text. Animated GOs offered no advantages over the large-bites GOs at first presentation and considerably extended total study time. Presenting several GOs first, followed by the entire text, appears to be optimal in directing students’ attention to across-chapter relations in text.     

Secondary teachers’ knowledge of elementary number theory proofs: the case of general-cover proofs

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.     

The continuous measurement of the springboard reaction force in gymnastic vaulting

A new method was established for the continuous measurement of force applied from a springboard to a gymnast in vaulting (board reaction force). Male gymnasts performed a handspring vault using a springboard mounted on force platforms. A high-speed video camera sampled the springboard motion at 500 Hz. The springboard was initially partitioned into 29 segments. The force due to the accelerative motion of the springboard was determined by summing the forces of the individual segments. The board reaction force acting on the gymnast was calculated by subtracting the force due to the accelerative motion of the springboard and weight from the force recorded by the force platform. The new method succeeded in illustrating transient changes of the board reaction force. The horizontal and vertical components of the peak values of the board reaction force were three and two times greater respectively than the average values. A series of tests was conducted to determine whether the number of segments of the springboard model could be reduced without affecting accuracy. A model consisting of only four segments produced almost the same accuracy as the 29-segment model. The simplified model is recommended as a more efficient method to measure board reaction force.     

Justification enlightenment and combining constructions of knowledge

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.     

Mobilizing for change: A study of research units in emerging scientific fields

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.     

Motor coordination difficulties in 5–6‐year‐old children with severe behavioural and emotional problems

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.     

The Future of Educational Psychology

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.