The role of representation in teaching and learning ideas about matter

The research described in this paper is designed around the notion that learning involves the recognition and development of students’ representational resources. This paper describes a classroom sequence in Ideas about Matter that focuses on representations and their negotiation, and reports on the effectiveness of this perspective in guiding teaching, and in providing further insight into student learning. Classroom sequences involving two experienced teachers (2008, Year 8 students) and an inexperienced teacher (2010, Year 7 students) were videotaped using a combined focus on the teacher and groups of students. Video analysis software was used to code the variety of representations used teachers and students, and sequences of representational negotiation. The paper reports on the effect of this approach on teacher pedagogy and on student learning of Ideas about Matter. The paper will present data from video of classroom activities, students’ work samples, student and teacher interviews and pre and post-unit testing, to explore what a representational focus might entail in teaching Ideas about Matter, and the role of representations in learning and reasoning and exploring scientific ideas.

A professional learning program based on a representation intensive pedagogical approach

A representation-intensive pedagogical approach challenges students to generate and negotiate the representations (text, graphs, models, diagrams) that constitute the discursive practices of science, rather than focusing on the text-based, definitional versions of concepts. Previous research conducted on a small scale with a few topics and teachers successfully demonstrated enhanced outcomes for students, in terms of sustained engagement with ideas, and quality learning, and for teachers’ enhanced pedagogical knowledge, and epistemological understanding. This paper explores the efficacy of embedding a representations-intensive pedagogical approach into a state-wide professional learning program that was delivered to Victorian secondary science teachers in 2010/2011. The professional learning program involved participating teachers undertaking two successive days of professional development, then completing a small classroom-based project in their schools before returning for the third day of professional development. The program was supported by online drupal website. In determining the impact of the professional learning program on the teachers’ practice data was collected in the form of program participant surveys, presentations of the teachers’ classroom-based projects, focus group interviews and phone interviews. Teachers demonstrated the applicability of this pedagogical approach by adapting it to a variety of science topics.

Empowering teachers through a professional learning program that focused on a representation intensive pedagogical approach

A representation-intensive pedagogical approach challenges students to generate and negotiate the representations (text, graphs, models, diagrams) that constitute the discursive practices of science, rather than focusing on the text-based, definitional versions of concepts. It thus represents a more active view of knowledge than traditional structural approaches. Previous research conducted on a small scale with a few topics and teachers, successfully demonstrated enhanced outcomes for students, in terms of sustained engagement with ideas, and quality learning, and for teachers enhanced pedagogical knowledge, and epistemological understanding. This paper explores the efficacy of embedding a representations-intensive pedagogical approach into a state-wide professional learning program that was delivered to secondary science teachers in Victoria, Australian, in 2010/2011. The professional learning program involved participating teachers undertaking two successive days of professional development, then completing a small classroom-based project in their schools before returning for the third day of professional development. The program was supported by on online drupal website. In determining the impact of the professional learning program on the teachers’ practice data was collected in the form of program participant surveys, presentations of the teachers’ classroom-based projects, focus group interviews and phone interviews.

A representation-intensive signature pedagogy for school science?

In this paper we examine Shulman’s notion of signature pedagogies for its usefulness extended to school science. We argue that school science is in an important sense an apprenticeship, and that calls for reform in school science are compatible with Shulman’s practice-based vision of professional learning. Two case studies of teaching and learning will be presented based on research in primary and secondary schools that involved working closely with teachers to develop and validate involving a representation-intensive pedagogy that lays claim to bringing school science closer to the knowledge building practices of science. Video images of classrooms, interviews with students and teachers, and documentation of students’ work, were used to construct insights into the teaching and learning process. It is argued that Shulman’s notion of professional practice as involving apprenticeships of knowledge, practice and identity provides a useful lens through which to view this innovation. Shulman’s characterisation of signature pedagogy is used to identify key features of the approach.

Exercising sociomathematical norms in classroom discourse about data representation : insights from one case study of a grade 6 lesson in Indonesia

This paper examines a research study to foster mathematical discourse about data representations among Indonesian students. It was situated in the context of implementing an Indonesian version of Realistic Mathematics Education, labelled as PMRI, in primary schools. A case study of one lesson involving Grade 6 students on the choice of data representations in Yogyakarta will be discussed. The analysis focused on the enacted social norms and sociomathematical norms during a wholeclass discussion and their impacts on students’ knowledge of data representations. The need for constant effort to enact these norms in classroom mathematical discourse is highlighted.

Screening women’s complicity in the holocaust : the problems of judgement and representation

This essay analyses the representation of female perpetrators in Holocaust fiction films, particularly in relation to the persecution of prisoners in the Nazi camps. The screening of women in general, and female perpetrators in particular, is shown to be problematic due to their frequent marginalisation and the gendered, voyeuristic ways in which women's bodies are often objectified in Holocaust films. While the actions of female perpetrators and their depiction in films pose acute problems of judgement and representation that need to be acknowledged, it is argued that films have the potential to effectively explore the issue of women's complicity in the Holocaust.

Racialized urban America and Holocaust film : negotiating the limits of representation

Sidney Lumet’s influential film The Pawnbroker (1964) is one of the earliest films to consider the encounter between Holocaust narratives and low-income, urban American racial minorities. As much concerned with contemporary ‘race relations’ in the United States as it is with the Nazis’ persecution of Europe’s Jews, the film intertwines the story of Holocaust survivor Sol Nazerman with the social tensions of 1960s America, represented in his relationship with the young Puerto Rican shop assistant Jesus Oritz. The film stylistically juxtaposes raw footage of concentration camp existence with dismal images of New York slum life. Against these backdrops, the protagonist’s climactic ‘silent scream’ emblematically merges the repressed trauma of the survivor with the filmmaker’s interest in race relations, a theme that has undergone various transformations in a number of films since. One film that contemporizes this encounter is Richard LaGravenese’s Freedom Writers (2007). As opposed to the tragic outcome of the pawnbroker’s induction into urban America, here the Holocaust is a redemptive tool that permits inner-city Black and Latino youth to contextualize their own suffering. After reading The Diary of Anne Frank, this group of ‘at-risk’ sophomores to inspired to collaborate on an ultimately successful effort to bring Miep Geis, the woman who sheltered Anne Frank, to speak at their high school. Foregrounded by the 1992 Los Angeles riots, gentiles teacher Erin Gruwell and savior Miep Geis transform the Holocaust from an amplified parallel of American slums into an event that permits the children of American postcoloniality to triumph in spite of their socio-economic circumstances. Underlining the tension between the Jewish specificity and unprecedented nature of the Holocaust, and the need to generate Holocaust narratives that intersect with intrinsically racialized American narratives, such films have significant implications for how collective memories of suffering are constructed and contested.

Sparse subspace representation for spectral document clustering

We present a novel method for document clustering using sparse representation of documents in conjunction with spectral clustering. An ℓ1-norm optimization formulation is posed to learn the sparse representation of each document, allowing us to characterize the affinity between documents by considering the overall information instead of traditional pair wise similarities. This document affinity is encoded through a graph on which spectral clustering is performed. The decomposition into multiple subspaces allows documents to be part of a sub-group that shares a smaller set of similar vocabulary, thus allowing for cleaner clusters. Extensive experimental evaluations on two real-world datasets from Reuters-21578 and 20Newsgroup corpora show that our proposed method consistently outperforms state-of-the-art algorithms. Significantly, the performance improvement over other methods is prominent for this datasets.

Object categorization via sparse representation of local features

Sparse representation has been introduced to address many recognition problems in computer vision. In this paper, we propose a new framework for object categorization based on sparse representation of local features. Unlike most of previous sparse coding based methods in object classification that only use sparse coding to extract high-level features, the proposed method incorporates sparse representation and classification into a unified framework. Therefore, it does not need a further classifier. Experimental results show that the proposed method achieved better or comparable accuracy than the well known bag-of-features representation with various classifiers.

The descent of Morgan in Australia: kinship representation from the Australian colonies

Morgan had two extraordinary disciples in Lorimer Fison and Alfred Howitt in Australia. They were inspired by Morgan’s kinship schedule and were profoundly engaged in the method and theory of the collection of kinship data and its interpretation. Fison began using the schedule in Fiji in 1869. Soon after his first contact with Howitt, in 1873, they changed the method of collection of kinship terminologies. This paper traces the shift from tabulated kinship lists to family trees and the use of sticks to represent relationships (nearly twenty years before Rivers’ celebrated ‘genealogical method’), as well as efforts to find new means of representing kinship through experimentation with ‘ graphic formulae’ inspired by chemical equations. These innovations first occurred through the gathering of kinship data about the Kŭnai of Gippsland, Victoria, and crucially involved close collaboration between Howitt and his Kŭnai consultant Tulaba. What was revealed in this process was an indigenous kinship system quite different from that found in other parts of colonial Australia known at the time. Fison and Howitt explained this system as transitional between two stages in terms of Morgan’s evolutionary scheme, but at the same time challenged the assumption that the general scheme could be applied to Australia. While the details of Morgan’s evolutionary stages have faded from view, the methods of collection, representation, transmission, comparison and interpretation of kinship data are still live issues in anthropology today. The kind of kinship system discovered in Gippsland involved neutralisation of the cross-parallel distinctions, distinctions that are otherwise typical of Australia. Such neutralisation can now be shown to occur elsewhere in Australia. There does indeed seem to have been a transition from a Dravidianate system with cross-parallel distinctions to ‘overlays’ of cross-parallel neutralisation, and finally a complete loss in some generations of such distinctions in the terminology. These discoveries open up possibilities of rebuilding a diachronic theory of kinship change and evolution, incorporating some of the insights of Fison and Howitt, though without their specific hypotheses, either of local developments in Gippsland or the grand scheme of Morgan.

Human identification from ECG signals via sparse representation of local segments

This work proposes a novel framework to extract compact and discriminative features from Electrocardiogram (ECG) signals for human identification based on sparse representation of local segments. Specifically, local segments extracted from an ECG signal are projected to a small number of basic elements in a dictionary, which is learned from training data. A final representation is extracted by performing a max pooling procedure over all the sparse coefficient vectors in the ECG signal. Unlike most of existing methods for human identification from ECG signals which require segmentation of individual heartbeats or extraction of fiducial points, the proposed method does not need to segment individual heartbeats or detect any fiducial points. The method achieves an 99.48% accuracy on a 100 subjects dataset constructed from a publicly available database, which demonstrates that both local and global structural information are well captured to characterize the ECG signals.