Consolidation of Black-dyed Māori Textile Artefacts: Evaluating the Efficacy of Sodium Alginate

Black-dyed artefacts are found in museums worldwide, many produced using an iron-tannate compound. Deterioration of iron-tannate dyed artefacts is an international preservation issue: in New Zealand the deterioration of paru (iron-tannate) dyed Māori textiles is widespread. This article reports experimental work testing the efficacy of sodium alginate, a consolidant developed for deteriorated paru-dyed muka (fibre from harakeke; Phormium tenax). The colour stability, strength retention, and acidity of paru-dyed muka consolidated with sodium alginate (0.25, 0.5, and 1% w/v in water) was tested pre- and post-artificial light ageing. This study found that sodium alginate had no negative effect on paru-dyed muka and in some cases provided benefit. Interestingly, the colour of paru-dyed muka is substantially more stable in UV-filtered light than previously recognised. Also microfading results were in agreement with visual assessments of colour change at 1 Mlux hour exposure, providing confidence in this relatively new technique to assess colour change.     

Differing Roles,Differing Concerns: Using Network Analysis as a Tool to Highlight Diverging Concerns and Priorities Surrounding Teacher Education at Minority-Serving Institutions

Abstract

Minority-serving institutions are important in the production of teachers of color. However, this formative process is not without limitations. This multisite, multistate study relied on network analysis techniques to unveil timely and relevant concerns that students, faculty, and administrators identified as critical toward the strengthening of teacher production.     

Scientific concept development in Solomon Island students: a comparative analysis

Abstract

This paper summarises the results of an investigation of Solomon Islands secondary school students’ interpretations of three concepts: vision, animals and burning. Internal comparisons among the three areas and external comparisons with findings reported from other societies are made. While some support is given to the idea that children from different cultures may develop similar conceptions, this support is qualified and is shown to be dependent on the type of phenomenon investigated. The degree to which there is immediate personal experience of phenomena may be important, as may the presence or absence of culturally supported explanations. The commonly reported resistance of children's conceptions to school science teaching is also shown not to be universally true. The article ends with a plea for caution in the cross‐cultural extrapolation of research into children's conceptions.     

Contemporary Scientists and their Interactions with Non-Scientists: Alternative Companion Stories for School Curricula

Research in Science Education - Students learn more than science knowledge in a science classroom; they also acquire important messages about the purposes and contexts of science. Roberts (2011)...     

Classroom environments that foster a disposition for critical thinking

In this article, we examine the disposition for critical thinking (CT) from three perspectives and analyse the underlying constructs of the disposition for CT, such as one’s ability, sensitivity and inclination to engage in critical, mindful thought. Environmental factors that enhance or inhibit the development of a generalisable disposition for critical thought are discussed. Finally, we present a set of empirically-verified classroom practices that can help to foster a disposition for CT.     

The Bicycle Assembly Line Game

“The Bicycle Assembly Line Game” is a team‐based, in‐class activity that helps students develop a basic understanding of continuously operating processes. Each team of 7–10 students selects one of seven prefigured bicycle assembly lines to operate. The lines are run in real‐time, and the team that operates the line that yields the highest revenue wins. Students learn through discovery “What drives output rate?”; “How is capacity managed relative to market demand?”; and “Why does inventory accumulate?” Because task times are constant, the game provides a nice lead‐in to the topic of line balancing. This game has been successfully used in both undergraduate‐ and MBA‐level operations management courses.     

Genetic influences in different aspects of language development: the etiology of language skills in 4.5-year-old twins

The genetic and environmental etiologies of diverse aspects of language ability and disability, including articulation, phonology, grammar, vocabulary, and verbal memory, were investigated in a U.K. sample of 787 pairs of 4.5-year-old same-sex and opposite-sex twins. Moderate genetic influence was found for all aspects of language in the normal range. A similar pattern was found at the low end of the distribution with the exception of two receptive measures. Environmental influence was mainly due to nonshared factors, unique to the individual, with little influence from shared environment for most measures. Genetic and environmental influences on language ability and disability are quantitatively and qualitatively similar for males and females.     

Effect of Rasch Calibration on Ability and DIF Estimation in Computer-Adaptive Tests

In a previous simulation study of methods for assessing differential item functioning (DIF) in computer-adaptive tests (Zwick, Thayer, & Wingersky, 1993, 1994), modified versions of the Mantel-Haenszel and standardization methods were found to perform well. In that study, data were generated using the 3-parameter logistic (3PL) model and this same model was assumed in obtaining item parameter estimates. In the current study, the 3PL data were used but the Rasch model was assumed in obtaining the item parameter estimates, which determined the information table used for item selection. Although the obtained DIF statistics were highly correlated with the generating DIF values, they tended to be smaller in magnitude than in the 3PL analysis, resulting in a lower probability of DIF detection. This reduced sensitivity appeared to be related to a degradation in the accuracy of matching. Expected true scores from the Rasch-based computer-adaptive test tended to be biased downward, particularly for lower-ability examinees