The asymptotic posterior normality of the latent trait in an IRT model

It has long been part of the item response theory (IRT) folklore that under the usual empirical Bayes unidimensional IRT modeling approach, the posterior distribution of examinee ability given test response is approximately normal for a long test. Under very general and nonrestrictive nonparametric assumptions, we make this claim rigorous for a broad class of latent models.This research was partially supported by Office of Naval Research Cognitive and Neural Sciences Grant N0014-J-90-1940, 442-1548, National Science Foundation Mathematics Grant NSF-DMS-91-01436, and the National Center for Supercomputing Applications. We wish to thank Kumar Joag-dev and Zhiliang Ying for enlightening suggestions concerning the proof of the basic result.The authors wish to thank Kumar Joag-Dev, Brian Junker, Bert Green, Paul Holland, Robert Mislevy, and especially Zhiliang Ying for their useful comments and discussions.     

Processing reduced word forms: the suffix restoration effect

Listeners cannot recognize highly reduced word forms in isolation, but they can do so when these forms are presented in context (Ernestus, Baayen, & Schreuder, 2002). This suggests that not all possible surface forms of words have equal status in the mental lexicon. The present study shows that the reduced forms are linked to the canonical representations in the mental lexicon, and that these latter representations induce reconstruction processes. Listeners restore suffixes that are partly or completely missing in reduced word forms. A series of phoneme-monitoring experiments reveals the nature of this restoration: the basis for suffix restoration is mainly phonological in nature, but orthography has an influence as well.     

Stress priming in picture naming: an SOA study

This study investigates whether or not the representation of lexical stress information can be primed during speech production. In four experiments, we attempted to prime the stress position of bisyllabic target nouns (picture names) having initial and final stress with auditory prime words having either the same or different stress as the target (e.g., WORtel-MOtor vs. koSTUUM-MOtor; capital letters indicate stressed syllables in prime-target pairs). Furthermore, half of the prime words were semantically related, the other half unrelated. Overall, picture names were not produced faster when the prime word had the same stress as the target than when the prime had different stress, i.e., there was no stress-priming effect in any experiment. This result would not be expected if stress were stored in the lexicon. However, targets with initial stress were responded to faster than final-stress targets. The reason for this effect was neither the quality of the pictures nor frequency of occurrence or voice-key characteristics. We hypothesize here that this stress effect is a genuine encoding effect, i.e., words with stress on the second syllable take longer to be encoded because their stress pattern is irregular with respect to the lexical distribution of bisyllabic stress patterns, even though it can be regular with respect to metrical stress rules in Dutch. The results of the experiments are discussed in the framework of models of phonological encoding.     

Judgments of Aggressive, Withdrawn and Prosocial Behavior: Perceived Control, Anger, Pity and Sympathy in Young Dutch Children

In two studies, we examined first- and second-grade children's judgments of aggressive, withdrawn, and prosocial behavior by means of fictional scenarios. In study I, we compared judgments of fictional aggressive children with those of fictional withdrawn children. Aggressive children were perceived as more responsible for their behavior and elicited more feelings of anger, while withdrawn children were more likely to be chosen as a friend and elicited more feelings of pity. In study II, we compared judgments of fictional aggressive, withdrawn, and prosocial children with each other. Again aggressive children elicited the strongest feelings of anger, while withdrawn children elicited the strongest feelings of pity. These withdrawn children were perceived as more similar to the prosocial children. In an attempt to test the ecological validity of our sympathy measure, we asked children to rate their peers on a three-point liking scale and checked the scores of those judged to be aggressive by their teachers. These aggressive children were found to receive the lowest liking scores. The results are discussed.     

Are there degrees of belief?

John Maynard Keynes claimed that not all probabilities were comparable. Frank Ramsey argued that they were, and that Keynes's views to the contrary rested on a confusion of degree of entailment and degree of belief. We will argue that Keynes and Ramsey largely talked past each other, and yet that there are issues of great significance underlying their dispute. In particular, the simple principle of maximizing expected utility may be seen in a new light as one step of a rich and complex process.     

"荷兰假说"带给我们的启示--对哮喘和COPD认识的争论

1961年,Orie教授提出荷兰理论,认为哮喘与慢性阻塞性肺疾病（COPD）为同一病种而具有不同表现。而当前理论认为二者为独立疾病而有相似表现。争议持续至今已整整50年。哮喘与COPD的重叠现象一直让临床医生感到困惑,并带来临床的一些实际问题。我们期待更多的研究以及将来的指南给予更明确的阐述。     

Examining a model of dispositional mindfulness, body comparison, and body satisfaction

The present study examined the links between dispositional mindfulness, body comparison, and body satisfaction. It was expected that mindfulness would be associated with less body comparison and more body satisfaction. Two models were tested: one exploring body comparison as a mediator between mindfulness and body satisfaction and an alternative model exploring mindfulness as a mediator between body comparison and body satisfaction. In an online survey, 1287 Dutch women answered questions concerning dispositional mindfulness, body comparison, and body satisfaction. Results showed that body comparison was related negatively to both dispositional mindfulness and body satisfaction, whereas the two latter variables were related positively. Body comparison partially mediated the relation between mindfulness and body satisfaction. However, a stronger indirect effect was noted in the alternative model, where mindfulness partially mediated the link between body comparison and body satisfaction.     

The Time Course of Verb Processing in Dutch Sentences

The verb has traditionally been characterized as the central element in a sentence. Nevertheless, the exact role of the verb during the actual ongoing comprehension of a sentence as it unfolds in time remains largely unknown. This paper reports the results of two Cross-Modal Lexical Priming (CMLP) experiments detailing the pattern of verb priming during on-line processing of Dutch sentences. Results are contrasted with data from a third CMLP experiment on priming of nouns in similar sentences. It is demonstrated that the meaning of a matrix verb remains active throughout the entire matrix clause, while this is not the case for the meaning of a subject head noun. Activation of the meaning of the verb only dissipates upon encountering a clear signal as to the start of a new clause.     

Optimism and Revolt of the Oppressed: A Comparison of Two Polish Jewish Ghettos of World War II

One World War II Jewish ghetto that revolted, the Warsaw Ghetto, is compared to one that did not, the Lodz Ghetto, in order to examine the causes of violent resistance. This structured focused comparative method (George, 1979) illuminates problems with previous explanations for revolt and nonrevolt in Jewish ghettos and suggest psychological variables that might have led to or precluded organized violence. Specifically, it appears that these two ghettos differed in their perceptions about their future. The residents of the Warsaw Ghetto believed they had no hope of survival while residents of the Lodz Ghetto remained optimistic. These differing perceptions seem to have led to the different outcomes. Possible causes of these percetpions are also discussed.     

The recognition of phonologically assimilated words does not depend on specific language experience

In a series of 5 experiments, we investigated whether the processing of phonologically assimilated utterances is influenced by language learning. Previous experiments had shown that phonological assimilations, such as /lean#bacon/ → [leam bacon], are compensated for in perception. In this article, we investigated whether compensation for assimilation can occur without experience with an assimilation rule using automatic event-related potentials. Our first experiment indicated that Dutch listeners compensate for a Hungarian assimilation rule. Two subsequent experiments, however, failed to show compensation for assimilation by both Dutch and Hungarian listeners. Two additional experiments showed that this was due to the acoustic properties of the assimilated utterance, confirming earlier reports that phonetic detail is important in compensation for assimilation. Our data indicate that compensation for assimilation can occur without experience with an assimilation rule, in line with phonetic-phonological theories that assume that speech production is influenced by speech-perception abilities.