Exploring the Development of Pre-Service Science Elementary Teachers’ Pedagogical Content Knowledge

This paper explores how a group of pre-service elementary science student teachers came to understand the development of their Pedagogical Content Knowledge (PCK) over the course of a semester??s study in a science methods course. At the start of the semester, PCK was introduced to them as an academic construct and as a conceptual tool that they could use to plan for, and assess, the development of their professional knowledge and practice as beginning science teachers. All participants were provided with a tool known as a CoRe (Content Representation) and the manner in which they worked with the CoRe was such that it supported them in planning for and assessing their own learning about teaching elementary science through a focus on the development of their PCK. Through analysis of data derived from the application of a CoRe based methodology (modified and adapted for this study) to the teaching of the science topic of Air, participants?? reasons for, confidence in, and perceived meaningfulness of their learning about science teaching could be examined. In so doing, the nature of participants?? PCK development over time was made explicit. The results illustrate real possibilities for ways of enhancing student teachers?? ongoing professional learning in teacher preparation and offer a window into how the nature of PCK in pre-service education might be better understood and developed.     

Skiing

The purpose of the investigation was to study the relationship between thrust phase duration, ground reaction force, velocity increase after pole thrust and pole angles versus pole length during double poling in roller skiing. Seven male regional elite cross‐country skiers volunteered as subjects for the study. The subjects performed a maximal double pole thrust on roller skis with each of the three different pole lengths: ‘short’, self‐selected (normal) and ‘long’. The short and long poles were 7.5 cm shorter and 7.5 cm longer than the self‐selected pole length. The subjects made seven maximal pole thrusts with each pole length, which were randomly selected during 21 trials. For each trial the subjects accelerated from a 1.2 m high downhill slope attaining a speed of 3.92 m.s^‐1 before making a maximal double pole thrust on a force plate placed at the bottom of the slope. The vertical (F_z), anterior‐posterior (F_y) and medio‐lateral (F_x) reaction forces of the left pole were measured by the force plate. The positions of the pole were recorded in 3‐D by an opto‐electronic system. Thrust phase duration, impulse, mean force, velocity increase after pole thrust and pole angles were calculated from the recorded data. Double poling with long poles produced a significantly larger propulsive anterior‐posterior reaction force impulse and velocity increase than normal (p < .05) and short poles (p < .05). This was in spite of a larger mean anterior‐posterior reaction force being produced with short poles. Thus, thrust phase duration was a primary factor in determining propulsive anterior‐posterior impulse. For the practitioner, the results can be useful in the selection of pole length when the aim is to increase thrust phase duration, anterior‐posterior force impulse and velocity.     

A new device for measuring ski running surface force and pressure profiles

The pressure/force acting between the running surface of a ski and the snow may indirectly change glide friction. Thus, measuring the pressure/force distribution may be important for a deeper understanding of glide in skiing. The present aim was to construct a device that allowed the pressure/force underneath the ski running surface (SRS) to be recorded. Pressure sensors were attached on top of a platform. Sheets of different materials were used to improve the interaction between the SRS and the sensors. Possible functions of the device are demonstrated in three applications that emphasized comparison of force distribution underneath skis selected for similarity, force distribution under both skis and a single ski as well as backward weight distribution. The results show that the device with the pressure sensors mapped pressure/force distribution underneath the skis in the applications presented, and the system can thus be a useful tool for further optimizing e.g., ski designs.     

When Teaching Makes a Difference: Developing science teachers’ pedagogical content knowledge through learning study

It is a common view that developing teachers’ competence to restructure or reframe their knowledge and beliefs is inevitably a complex challenge. This paper reports on a research project with the aim to develop science teachers’ pedagogical content knowledge (PCK) through their participation in a learning study. A learning study is a collegial process in which teachers work together with a researcher to explore their own teaching activities in order to identify what is critical for their students’ learning. During one semester, three secondary science teachers worked in a learning study together with a researcher in a cyclical process in order to create prerequisites and further identify conditions for students’ learning. During the learning study, data were collected from video-recorded lessons and stimulated recall sessions in which the teachers and the researcher reflected on the lessons to analyze their development of PCK, their students’ learning and the impact of that knowledge on their own teaching. The results provide an insight into how the teachers developed their self-understanding in which they questioned their own epistemological beliefs, aims and objectives of teaching and taken-for-granted assumptions about science teaching and learning. As such, the study provides an understanding of teacher professional learning through a careful investigation of how teachers’ PCK is enhanced through their participation in the learning study, and further, how students’ learning might be developed as a consequence.     

Making PCK Explicit—Capturing Science Teachers’ Pedagogical Content Knowledge (PCK) in the Science Classroom

One way for teachers to develop their professional knowledge, which also focuses on specific science content and the ways students learn, is through being involved in researching their own practice. The aim of this study was to examine how science teachers changed (or not) their professional knowledge of teaching after inquiring into their own teaching in learning studies. The data used in this article consisted of interviews and video-recorded lessons from the six teachers before the project (PCK pre-test) and after the project (PCK post-test), allowing an analysis of if and if then how the teachers changed their teaching practice. Hence, this study responds to the urgent call to focus direct attention on the practice of science teaching. When looking at the individual teachers, it was possible to discern similarities in the ways they have changed their teaching in lesson 2 compared to lesson 1, changes that can be described as: changes in how the object of learning was defined and focused, changes in how the examples that were presented to the students were chosen and changes in how the lessons were structured which in turn influenced the meaning of the concepts that were dealt with. As such, issues for enhancing teachers’ professional learning were unpacked in ways that began to demonstrate, and offer insights into, the extent of their PCK development over time.     

Internet Based Activities (IBAs): Seniors' Experiences of the Conditions Required for the Performance of and the Influence of these Conditions on their Own Participation in Society

The digital gap is a threat to the participation of senior citizens in society, as a large proportion of seniors are not involved in Internet based activities (IBAs). To be able to overcome this disadvantage for seniors, there is a need to both learn more about the conditions that make seniors start performing IBAs and to be able to provide them with the most beneficial professional interventions. The aim of this study was to explore and describe seniors' experiences with IBAs. Qualitative interviews were conducted with 10 seniors (aged: 66–82 years) with a variety of experiences with IBAs, and the interviews were analyzed with the constant comparative method. The results reveal three categories that describe the experiences of the established performers, the new performers of IBAs in the process of starting out, and the nonperformers. The variations in performance were influenced by the meaning that the performance of IBAs had for the seniors. In addition, the seniors were affected by several other conditions—such as the support available in their environment, including access to knowledge—as this could encourage them to develop their performance. Basic aspects, such as having access to a computer and to the Internet had been arranged for the performers of IBAs. The different ways of performing IBAs, revealed in the three categories, influenced how the seniors viewed their opportunities to participate in society. The conclusion highlights the finding that professionals should consider a multitude of conditions when introducing seniors to the performance of meaningful IBAs.     

Exploring the Relation Between Prenatal and Neonatal Complications and Later Autistic-Like Features in a Representative Community Sample of Twins

Prenatal and neonatal events were reported by parents of 13,690 eighteen-month-old twins enrolled in the Twins Early Development Study, a representative community sample born in England and Wales. At ages 7–8, parents and teachers completed questionnaires on social and nonsocial autistic-like features and parents completed the Childhood Asperger Syndrome Test. Correlations between prenatal and neonatal events and autistic-like features were weak, both in the whole sample ( r  = .00–.07) and at the 5% quantitative extreme (phenotypic group correlations = .01–.11), after controlling for socioeconomic status and cognitive ability. Neonatal problems showed modest heritability (13%–14%) and significant shared and nonshared environmental influences (55%–59% and 28%–31%, respectively). Differences in identical twins' neonatal problems correlated weakly with their difference scores on autistic-like features ( r  = .01–.06).     

Public and Popular: British and Swedish Audience Trends in Factual and Reality Television

The research in this article examines audience responses to a range of factual and reality genres. It takes as a starting point that television audiences do not experience news or documentary or reality TV in isolation but as part of a range of factual and reality programmes. Factual and reality programming includes a broad understanding of non-fictional programming on broadcast television, satellite, cable and digital television. The breakdown of factual and reality programming into specific genres includes news, current affairs, documentary, and reality programmes, with further sub genres applied within each of these categories. This article critically examines genre evaluation. The quantitative research in this article is based on two national representative surveys conducted in Britain and Sweden. In both Britain and Sweden, programme makers have moved towards a reliance on popular factual genres. In Britain this is across all channels, and in Sweden this is mainly concentrated on commercial channels. Whilst there is still a commitment to news, there is an increasing use of hybrid genres in an attempt to popularise factual output. The impact of this changing generic environment on audiences is that in both countries viewers have reacted by drawing a line between traditional and contemporary factual genres. It is precisely because of the redrawing of the factual map that viewers rely on traditional ways of evaluating genres as public and informative, or popular and entertaining. The data provides evidence that contributes to existing debate on television genre, public service broadcasting, and media literacy skills. The central argument in this article is that genre evaluation is connected with wider socio-cultural discourses on public service broadcasting and popular culture, and that these are common social and cultural values that are shared by national audiences in two Northern European countries.     

Hierarchical Clustering Using Non-Greedy Principal Direction Divisive Partitioning

We present a non-greedy version of the recently published Principal Direction Divisive Partitioning (PDDP) algorithm. The PDDP algorithm creates a hierarchical taxonomy of a data set by successively splitting the data into sub-clusters. At each level the cluster with largest variance is split by a hyper-plane orthogonal to its leading principal component. The PDDP algorithm is known to produce high quality clusters, especially when applied to high dimensional data, such as document-word feature matrices. It also scales well with both the size and the dimensionality of the data set. However, at each level only the locally optimal choice of spitting is considered. At a later stage this often leads to a non-optimal global partitioning of the data. The non-greedy version of the PDDP algorithm (NGPDDP) presented in this paper address this problem. At each level multiple alternative splitting strategies are considered. Results from applying the algorithm to generated and real data (feature vectors from sets of text documents) are presented. The results show substantial improvements in the cluster quality.     

Acculturative Stress and Depressive Symptomatology Among Mexican and Mexican American Students in the U.S.: Examining Associations with Cultural Incongruity and Intragroup Marginalization

This study examined associations of intragroup marginalization and cultural incongruity with acculturative stress and depressive symptoms among 155 undergraduate U.S. college students of Mexican heritage. Findings indicate that perceived interpersonal distancing by the family (intragroup marginalization) and perceived lack of cultural fit between the respondent and academic institution (cultural incongruity) had statistically significant direct and indirect effects on depressive symptoms via acculturative stress. Results also show that 39.7 % of the variance corresponding with depressive symptoms was accounted for by intragroup marginalization, cultural incongruity, acculturative stress, and other exogenous variables.