Evaluating a dual‐process model of risk: affect and cognition as determinants of risky choice

In three studies we addressed the impact of perceived risk and negative affect on risky choice. In Study 1, we tested a model that included both perceived risk and negative affect as predictors of risky choice. Study 2 and Study 3 replicated these findings and examined the impact of affective versus cognitive processing modes. In all the three studies, both perceived risk and negative affect were shown to be significant predictors of risky choice. Furthermore, Study 2 and Study 3 showed that an affective processing mode strengthened the relation between negative affect and risky choice and that a cognitive processing mode strengthened the relation between perceived risk and risky choice. Together, these findings show support for the idea of a dual‐process model of risky choice. Copyright © 2008 John Wiley & Sons, Ltd.     

Optimum sample size allocation to minimize cost or maximize power for the two‐sample trimmed mean test

When planning a study, sample size determination is one of the most important tasks facing the researcher. The size will depend on the purpose of the study, the cost limitations, and the nature of the data. By specifying the standard deviation ratio and/or the sample size ratio, the present study considers the problem of heterogeneous variances and non‐normality for Yuen's two‐group test and develops sample size formulas to minimize the total cost or maximize the power of the test. For a given power, the sample size allocation ratio can be manipulated so that the proposed formulas can minimize the total cost, the total sample size, or the sum of total sample size and total cost. On the other hand, for a given total cost, the optimum sample size allocation ratio can maximize the statistical power of the test. After the sample size is determined, the present simulation applies Yuen's test to the sample generated, and then the procedure is validated in terms of Type I errors and power. Simulation results show that the proposed formulas can control Type I errors and achieve the desired power under the various conditions specified. Finally, the implications for determining sample sizes in experimental studies and future research are discussed.     

Fixed‐links models for investigating experimental effects combined with processing strategies in repeated measures designs: A cognitive task as example

Fixed‐links models enable the investigation of experimental effects in combination with processing strategies in the framework of repeated measures designs. The consideration of different processing strategies is reasonable whenever the task requirements can be met in different ways. Effects due to specific processing strategies become obvious in comparing the models representing these processing strategies and also by investigating the variances of the corresponding latent variables. The usefulness of such models is demonstrated by the reaction time data of a cognitive task including three treatment levels. Two different processing strategies were considered: analytic and holistic. The results indicated that the participants applied both processing strategies. The analytic strategy was primarily applied for performing with respect to the second and third treatment levels and the holistic strategy with respect to the first treatment level.     

The maximum priority index method for severely constrained item selection in computerized adaptive testing

This paper introduces a new heuristic approach, the maximum priority index (MPI) method, for severely constrained item selection in computerized adaptive testing. Our simulation study shows that it is able to accommodate various non‐statistical constraints simultaneously, such as content balancing, exposure control, answer key balancing, and so on. Compared with the weighted deviation modelling method, it leads to fewer constraint violations and better exposure control while maintaining the same level of measurement precision.     

An effect size index for comparing two independent alpha coefficients

Since Cronbach proposed the α coefficient in 1951, researchers have contributed to the derivation of its sampling distribution and the testing of related statistical hypotheses. Yet, there has been no research on effect size index relevant to coefficient α to our knowledge. Considering the importance of effect size in understanding quantitative research findings, we therefore developed an effect size index Δ for the comparison of two independent αs with equal test length based on the asymptotic distribution of under the assumptions of normality and compound symmetry. Simulations indicated that the index was applicable when the sample size was at least 100. The robustness of the derived index when the required assumptions were violated was also explored. It is suggested that the index should be applicable in most cases of unequal test lengths and could be extended to non‐normally distributed component scores. Moreover, a small simulation was conducted to explore the behaviour of Δ with correlated errors, a frequently studied situation violating the assumption of compound symmetry. The proposed index was found to be robust unless a large number of highly correlated errors were present in the data.     

The word concreteness effect occurs for positive,but not negative,emotion words in immediate serial recall

The present study examined the roles of word concreteness and word valence in the immediate serial recall task. Emotion words (e.g. happy) were used to investigate these effects. Participants completed study‐test trials with seven‐item study lists consisting of positive or negative words with either high or low concreteness (Experiments 1 and 2) and neutral (i.e. non‐emotion) words with either high or low concreteness (Experiment 2). For neutral words, the typical word concreteness effect (concrete words are better recalled than abstract words) was replicated. For emotion words, the effect occurred for positive words, but not for negative words. While the word concreteness effect was stronger for neutral words than for negative words, it was not different for the neutral words and the positive words. We conclude that both word valence and word concreteness simultaneously contribute to the item and order retention of emotion words and discuss how Hulme et al.'s (1997) item redintegration account can be modified to explain these findings.     

Decomposing self‐estimates of intelligence: Structure and sex differences across 12 nations

This study examines the structure of self‐estimates of intelligence (SEI) across 12 nations (Australia, Austria, Brazil, France, Iran, Israel, Malaysia, South Africa, Spain, Turkey, UK and US). Participants rated themselves on general and specific abilities from three popular models of intelligence: Gardner's multiple intelligences, Sternberg's triarchic theory of intelligence, and Goleman's emotional intelligence. The results showed that (a) laypeople across nations have similar and invariant concepts of intelligence, (b) concepts of intelligence are cross‐culturally closely related to academic notions of intellectual ability and (c) sex differences in general and specific SEI favouring men are consistent across countries. Male hubris and female humility in SEI seem independent of sex differences in actual cognitive ability and national levels of masculinity‐femininity. Furthermore, international mean differences in general SEI could not be attributed to discrepancies in national intelligence quotient (IQ) levels or to cultural variations.     

Improving self‐regulated learning of preschool children: Evaluation of training for kindergarten teachers

Background In the context of lifelong learning, self‐regulated learning is an important competence. Children between 4 and 6 years of age are at a crucial step in their life to develop self‐regulatory competence. That is why their kindergarten teachers play an important role as instructors as well as role models. Aim This study tested the effects of self‐regulation training for kindergarten teachers concerning their own self‐regulation and methods to foster self‐regulation in children at preschool age whom they were teaching. Sample In this study, 35 German kindergarten teachers and 97 children participated. All adult participants were graduated kindergarten teachers. Method The kindergarten teachers were tested with a questionnaire 2 weeks before and after the training. At the same time, the preschoolers were interviewed. A waiting control group design was applied. Results and conclusions The results obtained by means of analyses of variance show that the self‐regulation of the kindergarten teachers as well as the self‐regulated learning of preschoolers whose kindergarten teachers took part in the training improved significantly. The results indicate that it is possible to improve self‐regulated learning of preschool children by a training programme for kindergarten teachers.     

Iterating between lessons on concepts and procedures can improve mathematics knowledge

Background Knowledge of concepts and procedures seems to develop in an iterative fashion, with increases in one type of knowledge leading to increases in the other type of knowledge. This suggests that iterating between lessons on concepts and procedures may improve learning. Aims The purpose of the current study was to evaluate the instructional benefits of an iterative lesson sequence compared to a concepts‐before‐procedures sequence for students learning decimal place‐value concepts and arithmetic procedures. Samples In two classroom experiments, sixth‐grade students from two schools participated (N = 77 and 26). Method Students completed six decimal lessons on an intelligent‐tutoring systems. In the iterative condition, lessons cycled between concept and procedure lessons. In the concepts‐first condition, all concept lessons were presented before introducing the procedure lessons. Results In both experiments, students in the iterative condition gained more knowledge of arithmetic procedures, including ability to transfer the procedures to problems with novel features. Knowledge of concepts was fairly comparable across conditions. Finally, pre‐test knowledge of one type predicted gains in knowledge of the other type across experiments. Conclusions An iterative sequencing of lessons seems to facilitate learning and transfer, particularly of mathematical procedures. The findings support an iterative perspective for the development of knowledge of concepts and procedures.