Social Studies in the Modern Era: A Case Study of Effective Teachers' Use of Literacy and Technology

The purpose of this research project was to highlight the practices and philosophies of two effective—but different—social studies teachers who balance the demands of teaching in the modern era while honoring their own philosophies for teaching social studies. This project was ground in the theoretical framework provided by TPACK and used a case study methodology for its research design. While the pedagogical content knowledge of the participants was strong and technology was used abundantly for instructional purposes, this research raised questions regarding how teachers can most effectively use technology to enhance instruction by helping students conceptualize content knowledge and apply their learning in new ways.     

Preference for Flexibility and Random Choice

We study a two‐stage model where the agent has preferences over menus as in Dekel, Lipman, and Rustichini (2001) in the first period and then makes random choices from menus as in Gul and Pesendorfer (2006) in the second period. Both preference for flexibility in the first period and strictly random choices in the second period can be, respectively, rationalized by subjective state spaces. Our main result characterizes the representation where the two state spaces align, so the agent correctly anticipates her future choices. The joint representation uniquely identifies probabilities over subjective states and magnitudes of utilities across states. We also characterize when the agent completely overlooks some subjective states that realize at the point of choice.     

The Self-serving Bias and Beliefs about Rationality

Most previous experiments attempting to establish the existence of the self-serving bias have confounded it with strategic behavior. We design an experiment that controls for strategic behavior (Haman effects) and isolates the bias itself. The self-serving bias that we measure concerns beliefs about the rationality of others. We find very limited support for the existence of the bias. To help understand why the bias seems to hold in some settings but not in others, we discuss a distinction between biases that are self-serving and those that are actually self-defeating. (JEL C92 )     

Common Mechanisms in Infant and Adult Category Learning

Computational models of infant categorization often fail to elaborate the transitional mechanisms that allow infants to achieve adult performance. In this article, we apply a successful connectionist model of adult category learning to developmental data. The Supervised and Unsupervised Stratified Adaptive Incremental Network (SUSTAIN) model is able to account for the emergence of infants' sensitivity to correlated attributes (e.g., has wings and can fly). SUSTAIN offers 2 complimentary explanations of the developmental trend. One explanation centers on memory storage limitations, whereas the other focuses on limitations in perceptual systems. Both explanations parallel published findings concerning the cognitive and sensory limitations of infants. SUSTAIN's simulations suggest that conceptual development follows a continuous and smooth trajectory despite qualitative changes in behavior and that the mechanisms that underlie infant and adult categorization might not differ significantly.     

Testing the Determinants of Income Distribution in Major League Baseball

Using data from U.S. Major League Baseball, this article compares parametric and nonparametric Gini coefficients for each team and year. We employ a panel-data model to investigate the time-series and cross-sectional factors affecting the Gini coefficients and the parameters of the preselected distribution. We find that much of within-team income distribution is determined by time-related variables, with the 1994 MLB strike having an especially strong effect. A team's market potential does not seem to affect its salary distribution, but the average age of the players on a team's roster does. Furthermore, inequality first increases with team payroll, then decreases before increasing again.     

O Other,Where Art Thou? Support for Multiparty Politics in the United States*

Objective. We test hypotheses about support for multiparty politics in the United States. We expect that individual‐level attitudes and state‐level partisan context determine who supports having more parties. Methods. Survey data are used to model attitudes about having additional parties to challenge Democrats and Republicans. Results. Self‐identified partisans are opposed to additional parties, but independents who “lean” toward a major party are most supportive. Independents who say they are closer to Democrats, as well as independents who say they are closer to Republicans, tend to support having new parties. The latter effect is contingent on a state's partisan context. Independents closer to Republicans are most receptive to additional parties in states where fewer conservative representatives are elected. Conclusions. Support for multiparty‐ism among “leaning” independents challenges our understanding of how they may be similar to partisan identifiers, and illustrates that a base for new parties may exist in the “mainstream” public if electoral rules were changed.     

Comparison of sample size formulae for 2 × 2 cross‐over designs applied to bioequivalence studies

We consider the comparison of two formulations in terms of average bioequivalence using the 2 × 2 cross‐over design. In a bioequivalence study, the primary outcome is a pharmacokinetic measure, such as the area under the plasma concentration by time curve, which is usually assumed to have a lognormal distribution. The criterion typically used for claiming bioequivalence is that the 90% confidence interval for the ratio of the means should lie within the interval (0.80, 1.25), or equivalently the 90% confidence interval for the differences in the means on the natural log scale should be within the interval (?0.2231, 0.2231). We compare the gold standard method for calculation of the sample size based on the non‐central t distribution with those based on the central t and normal distributions. In practice, the differences between the various approaches are likely to be small. Further approximations to the power function are sometimes used to simplify the calculations. These approximations should be used with caution, because the sample size required for a desirable level of power might be under‐ or overestimated compared to the gold standard method. However, in some situations the approximate methods produce very similar sample sizes to the gold standard method. Copyright © 2005 John Wiley & Sons, Ltd.     

Intrasensory Redundancy Facilitates Infant Detection of Tempo: Extending Predictions of the Intersensory Redundancy Hypothesis

Research has demonstrated that intersensory redundancy (stimulation synchronized across multiple senses) is highly salient and facilitates processing of amodal properties in multimodal events, bootstrapping early perceptual development. The present study is the first to extend this central principle of the intersensory redundancy hypothesis (IRH) to certain types of intrasensory redundancy (stimulation synchronized within a single sense). Infants were habituated to videos of a toy hammer tapping silently (unimodal control), depicting intersensory redundancy (synchronized with a soundtrack) or intrasensory redundancy (synchronized with another visual event; light flashing or bat tapping). In Experiment 1, 2‐month‐olds showed both intersensory and intrasensory facilitation (with respect to the unimodal control) for detecting a change in tempo. However, intrasensory facilitation was found when the hammer was synchronized with the light flashing (different motion) but not with the bat tapping (same motion). Experiment 2 tested 3‐month‐olds using a somewhat easier tempo contrast. Results supported a similarity hypothesis: intrasensory redundancy between two dissimilar events was more effective than that between two similar events for promoting processing of amodal properties. These findings extend the IRH and indicate that in addition to intersensory redundancy, intrasensory redundancy between two synchronized dissimilar visual events is also effective in promoting perceptual processing of amodal event properties.