On the Bock-Aitkin procedure—From an EM algorithm perspective

The relationship between the EM algorithm and the Bock-Aitkin procedure is described with a continuous distribution of ability (latent trait) from an EM-algorithm perspective. Previous work has been restricted to the discrete case from a probit-analysis perspective. The author is grateful to Bradley A. Hanson for valuable discussion and comments. Thanks also go to Terry A. Ackerman, Meichu Fan, Subrata Kundu, and Robert K. Tsutakawa for their help and encouragement in this study.     

Place learning in virtual space III: Investigation of spatial navigation training procedures and their application to fMRI and clinical neuropsychology

This paper describes the utilization of a desktop virtual environment task, the Computer-Generated (C-G) Arena, in the study of human spatial navigation. First, four experiments examined the efficacy of various training procedures in the C-G Arena. In Experiment 1, participants efficiently located a hidden target after only observing the virtual environment from a fixed position (placement learning). In Experiment 2, participants efficiently located a hidden target after only observing an experimenter search the virtual environment (observational learning). In Experiment 3, participants failed to display alatent learning effect in the virtual environment. In Experiment 4, all training procedures effectively taught participants the layout of the virtual environment, but the observational learning procedure most effectivelytaught participants the location of a hidden target within the environment. Finally, two experiments demonstrated the application of C-G Arena procedures to neuroimaging (Experiment 5) and neuropsychological (Experiment 6) investigations of human spatial navigation.     

Taiwanese adolescents' intention model of visiting Internet cafés.

This study intended to construct an intention model of visiting Internet cafés. Four hundred eighty-three Taiwanese high school students were surveyed during March 2002. The results indicated that intention increased with positive attitude toward visiting Internet cafés, the intention was only rarely affected by significant others, intention strengthened with the quantity of resources and skills perceived, and past behavior negatively influenced the intention. Three conclusions were drawn: (a) The proposed model can effectively predict adolescent intention to visit Internet cafés. (b) Past behavior was the main predictor of intention. (3) In terms of intention to visit Internet cafés, there is a strengthening of individualism and a weakening of normative influences. Finally, suggestions and recommendations were made for practice and future research.     

Staging on the Internet: research on online photo album users in Taiwan with the spectacle/performance paradigm.

This study explores motivations of online photo album users in Taiwan and the distinctive "staging" phenomenon with media gratifications and an a priori theoretical framework, the spectacle/performance paradigm (SPP). Media drenching, performance, function and reference are "new" gratifications, which no prior research was found. These gratifications are consistent with the argument of the "diffused audience" on the Internet. This study verifies that the process-content distinction may not be applicable in the Internet setting because distinctions between the real world and the mediated world are vanishing, which is also the main argument of the SPP paradigm.     

Social anxiety in Chinese- and European-heritage students: the effect of assessment format and judgments of impairment

We examined whether social anxiety resulted in different levels of perceived impairment in first- and second-generation students of Chinese heritage (ns=65 and 47) compared to their European-heritage counterparts (n=60). We also used a modified version of the Anxiety Disorders Interview Schedule (ADIS-IV) to determine whether the 3 groups responded differently to the social demands inherent in interview-based assessment compared to questionnaires. First-generation Chinese participants reported significantly greater social anxiety and impairment than the European heritage group in response to both interviews and questionnaires. The results argue against the notion that social anxiety is perceived to cause less impairment in Chinese North Americans or that interview-based assessment has a differential effect on the Chinese- and European-heritage groups.     

Standing balance of children with developmental coordination disorder under altered sensory conditions

Maintenance of standing balance requires that sensory inputs be organized with the motor system. Current data regarding the influence of sensory inputs on standing balance in children with developmental coordination disorder (DCD) are limited. This study compared the influence of sensory organization and each sensory input on the standing stability between a group of 20 children, 4-6 years old, with DCD and an age- and gender-matched control group of 20 children. Three types of visual inputs (eyes open, eyes closed, or unreliable vision) and two types of somatosensory inputs (fixed or compliant foot support) were varied factorially to yield six sensory conditions. Standing stability was measured with a Kistler force plate for 30s and expressed as the center of pressure sway area. The results showed that the standing stability of the children with DCD was significantly poorer than that of the control children under all sensory conditions, especially when the somatosensory input was unreliable (compliant foot support) compared to when it was reliable (fixed foot support). The effectiveness of an individual sensory system, when it was the dominant source of sensory input, did not significantly differ between the groups. The results suggest that children with DCD experience more difficulty coping with altered sensory inputs, and that such difficulty is more likely due to a deficit in sensory organization rather than compromised effectiveness of individual sensory systems.     

A Speeded Item Response Model: Leave the Harder till Later

A speeded item response model is proposed. We consider the situation where examinees may retain the harder items to a later test period in a time limit test. With such a strategy, examinees may not finish answering some of the harder items within the allocated time. In the proposed model, we try to describe such a mechanism by incorporating a speeded-effect term into the two-parameter logistic item response model. A Bayesian estimation procedure of the current model using Markov chain Monte Carlo is presented, and its performance over the two-parameter logistic item response model in a speeded test is demonstrated through simulations. The methodology is applied to physics examination data of the Department Required Test for college entrance in Taiwan for illustration.     

Happiness and Regional Segmentation: Does Space Matter?

This paper examines cross-country happiness interdependencies. The sample under study includes 116 countries of diverse characteristics using averaged data for the year 2006. We divide the entire data into six groups of countries, viz., Income domain (developed and developing); Income inequality (equal and unequal); Level of political history (socialist and non-socialist). A spatial econometric technique is used to estimate the spillover effects of one country’s well-being on the well-being of the neighboring countries. Both spatial and non-spatial results indicate that corruption, health and national income serve as the best indicators of happiness for developed and equal countries, whereas unemployment affects the developing, non-socialist and unequal nations. Corruption appears to be the most significant factor, implying that a better quality government makes everybody happy. Furthermore, we find significant happiness spillovers among the above specified groups, thus indicating the importance of group clustering in the studies of happiness. The result suggests that the more homogenous the group is, the higher will be the spillover among them. We observe positive spillover for developed countries and negative spillover for socialist and equal countries. Ignoring such spatial spillover effect may lead to misunderstanding of various policy implications.     

The Appeal to Expert Opinion: Quantitative Support for a Bayesian Network Approach

The appeal to expert opinion is an argument form that uses the verdict of an expert to support a position or hypothesis. A previous scheme‐based treatment of the argument form is formalized within a Bayesian network that is able to capture the critical aspects of the argument form, including the central considerations of the expert's expertise and trustworthiness. We propose this as an appropriate normative framework for the argument form, enabling the development and testing of quantitative predictions as to how people evaluate this argument, suggesting that such an approach might be beneficial to argumentation research generally. We subsequently present two experiments as an example of the potential for future research in this vein, demonstrating that participants' quantitative ratings of the convincingness of a proposition that has been supported with an appeal to expert opinion were broadly consistent with the predictions of the Bayesian model.     

Contest experience and body size affect different types of contest decisions

This study examined the relative importance of contest experience and size differences to behavioral decisions over the course of contests. Using a mangrove rivulus fish, Kryptolebias marmoratus, we showed that although contest experience and size differences jointly determined contest outcomes, they affected contestants’ interactions at different stages of contests. Contest experience affected behavioral decisions at earlier stages of contests, including the tendency and latency to launch attacks, the tendency to escalate contests into mutual attacks and the outcome of non-escalated contests. Once contests were escalated into mutual attacks, the degree of size difference affected the fish’s persistence in escalation and chance of winning, but contest experience did not. These results support the hypothesis that contest experience modifies individuals’ estimation of their fighting ability rather than their actual strength. Furthermore, (1) in contests between two naïve contestants, more than 60 % of fish that were 2–3 mm smaller than their opponent escalated the contest to physical fights, even though their larger opponents eventually won 92 % of escalated fights and (2) fish with a losing experience were very likely to retreat in the face of an opponent 2–3 mm smaller than them without escalating. The result that a 2–3 mm size advantage could not offset the influence of a losing experience on the tendency to escalate suggests that, as well as depending on body size, the fish’s physical strength is influenced by other factors which require further investigation.