A systems-level approach to building sustainable assessment cultures: moderation, quality task design and dependability of judgement

This paper considers the conditions that are necessary at system and local levels for teacher assessment to be valid, reliable and rigorous. With sustainable assessment cultures as a goal, the paper examines how education systems can support local level efforts for quality learning and dependable teacher assessment. This is achieved through discussion of relevant research and consideration of a case study involving an evaluation of a cross-sectoral approach to promoting confidence in school-based assessment in Queensland, Australia. Building on the reported case study, essential characteristics for developing sustainable assessment cultures are presented, including: leadership in learning; alignment of curriculum, pedagogy and assessment; the design of quality assessment tasks and accompanying standards, and evidence-based judgement and moderation. Taken together, these elements constitute a new framework for building assessment capabilities and promoting quality assurance

ToF-SIMS quantification of polystyrene spectra based on principal component analysis (PCA)

Monodisperses polystyrenes (PS) with molecular weight (M-n) ranging from 850 to 20 000 g mol(-1) and with different butyl end-groups have been analysed by time-of-flight secondary ion mass spectrometry (ToF-SIMS). Only the fingerprint part of the spectra (m/z < 200) has been considered. This part comes from the fragmentation of the macromolecules and this is the only contribution in the secondary ion spectra of bulk polymers. In a former study, it has been shown that M-n has a significant influence on the PS secondary molecular ion intensities, It was found that not only the end-group characteristic ion intensities are modified for M-n < 50 000 g mol(-1), but also those related to main chain fragments. In this study, the possibility to use this effect to quantify the molecular weight of the macrochains at the surface is investigated. Because the quantification method should preferably include all the information contained in the spectra (over 150 peaks), statistical methods are needed, Principal component analysis is applied to these ToF-SIMS data. Principal component analysis builds the best linear combination of the variables, namely the principal components that describe the greatest amount of variation of the sample set, It is found that only one principal component is required to account for the molecular weight variations and a second one allows the samples to be discriminated depending on their butyl end-groups. Whatever the PS end-groups (linear, secondary or tertiary butyl), the correlation found between the first principal component and the sample molecular weight leads to the definition of a universal curve that allows the molecular weight determination for an unknown monodisperse PS sample. (C) 1997 by John Wiley & Sons, Ltd

Evolution of applications and modelling in a senior secondary curriculum

In Queensland Australia, mathematical modelling and applications have featured in senior secondary mathematics curricula for two decades. Part of a longitudinal study of the implementation of this initiative, as seen through the eyes of selected teachers and administrators who have been centrally involved in its development and on-going practice, is reported. The data consist of responses to structured and open interview questions, syllabus documents, and application and modelling tasks designed and implemented by teachers. Perceptions of why modelling and applications are valuable at this level of schooling, the distinction between applications and modelling, how established applications and modelling are in the curriculum, the sources of such tasks, and the sufficiency of support for the development of these tasks by teachers are presented