The Role of Content Knowledge and Problem Features on Preservice Teachers’ Appraisal of Elementary Mathematics Tasks

The objective of this study was to examine the nature of preservice teachers’ evaluations of elementary mathematics problems using the Mathematical Tasks Framework (MTF), a model designed to discriminate among tasks according to their cognitive complexity. We also tested the relationship between mathematics content knowledge and problem length on the preservice teachers’ evaluations. Twenty-six undergraduate students enrolled in an elementary mathematics methods course at a large urban university were introduced to the MTF and cognitive complexity during a class lecture and were subsequently required to sort 32 mathematics problems according to the framework. Results demonstrated that overall, the preservice teachers had more difficulty accurately classifying problems considered to represent high levels of cognitive complexity compared to problems that were less complex. Those with strong mathematics content knowledge, as measured by a standardized test, were able to sort the problems more accurately than those with weaker content knowledge. Two open-ended items assessing content knowledge were not related to sorting performance. Finally, the preservice teachers were influenced by the surface characteristic of task length; the data indicated that the teachers tended to label short problems as less cognitively demanding and long problems as more so. Implications for preservice professional development include an increased emphasis on mathematics content knowledge as well as expert modeling of the identification of deep conceptual principles at the heart of the mathematics curriculum.     

EXPANDING YOUNG PEOPLE'S CAPACITY TO LEARN

Abstract:  Though it is being widely argued that expanding young people's capacity to learn is a viable and desirable goal of education, it it not always clear what this means, how it is to be achieved, and how the effectiveness of interventions is to be assessed. It is argued that the capacity to learn should be interpreted as a portmanteau term that comprises a varied set of positive learning dispositions. These are illustrated, and the idea of 'expansion' is glossed in terms of broadening, strengthening and deepening these dispositions.     

Continuous frequency and phase spectrograms： a study of their 2D and 3D capabilities and application to musical signal analysis

A new lighting and enlargement on phase spectrogram （PS） and frequency spectrogram （FS） is presented in this paper. These representations result from the coupling of power spectrogram and short time Fourier transform （STFT）. The main contribution is the construction of the 3D phase spectrogram （3DPS） and the 3D frequency spectrogram （3DFS）. These new tools allow such specific test signals as small slope linear chirp, phase jump case of musical signal analysis is reported. The main objective is to and small frequency jump to be analyzed. An application detect small frequency and phase variations in order to characterize each type of sound attack without losing the amplitude information given by power spectrogram     

A mathematical formulation of keyword compression for thesauri

In this paper we demonstrate a new method for concentrating the set of key-words of a thesaurus. This method is based on a mathematical study that we have carried out into the distribution of characters in a defined natural language.We have built a function f of concentration which generates only a few synonyms. In applying this function to the set of key-words of a thesaurus, we reduce each key-word to four characters without synonymity. (For three characters we have a rate of synonymity of approx. 1/1000th.)A new structure of binary files allows the thesaurus to be contained in a table of less than 700 bytes.     

Complementarities in organizational design and the diffusion of information technologies: An empirical analysis

We use a specially designed survey on French firms located in Haute-Savoie to provide empirical evidence suggesting that Information and Communication Technologies adoption is not only influenced by the traditional factors of technology diffusion but also by complementarity effects between strategies, organization and information technologies. The data collected permitted several advances. Firstly, we could study authentic ICT while the recent literature has mainly focused on computer capital stocks or automation tools. Secondly, we constructed measures of the determinants put forward by the models of technology diffusion. Thirdly, we studied three kinds of practices: organizational and strategic practices, technological choices.     

The mystery of the Einstein-Poincaré connection

This essay discusses attempts that have been made to explain the striking similarities between two theories propounded in 1905 by Albert Einstein and Henri Poincaré without any mutual reference.     

The (im)materiality of literacy: the significance of subjectivity to new literacies research

This article deconstructs the online and offline experience to show its complexities and idiosyncratic nature. It proposes a theoretical framework designed to conceptualise aspects of meaning-making across on- and offline contexts. In arguing for the ‘(im)materiality’ of literacy, it makes four propositions which highlight the complex and diverse relationships between the immaterial and material associated with meaning-making. Complementing existing sociocultural perspectives on literacy, the article draws attention to the significance of relationships between space, mediation, materiality and embodiment to literacy practices. This in turn emphasises the importance of the subjective in understanding how different locations, experiences and so forth inflect literacy practice. The article concludes by drawing on the Deleuzian concept of the ‘baroque’ to suggest that this focus on articulations between the material and immaterial helps us to see literacy as multiply and flexibly situated.     

Do null phonemic masking effects reflect strategic control of phonology?

Verstaen, Humphreys, Olson and D'Ydewalle [(1995) Journal of Memory and Language, 34, 335–356] reported null phonemic masking effectswith homophone targets under conditionsdiscouraging reliance on phonology. Theyattributed these null effects to the absence ofreliance on phonology, concluding that relianceon phonology may be strategically controlled. Two studies using Verstaen et al.'s methodoccasionally replicate these null phonemicmasking effects, but challenge theirinterpretation. The emergence of null phonemicmasking effects was unrelated to the strategymanipulation. Conversely, evidence forphonology emerged in homophone errorsregardless of the strategy manipulation anddespite null phonemic masking effects. Ourfindings reflect an inherent instability in theperception of homophones. We demonstrate thatthis instability is directly due to reliance onphonology, rather than to its control.