A sufficient condition for pooling data

We consider the problems arising from using sequences of experiments to discover the causal structure among a set of variables, none of whom are known ahead of time to be an “outcome”. In particular, we present various approaches to resolve conflicts in the experimental results arising from sampling variability in the experiments. We provide a sufficient condition that allows for pooling of data from experiments with different joint distributions over the variables. Satisfaction of the condition allows for an independence test with greater sample size that may resolve some of the conflicts in the experimental results. The pooling condition has its own problems, but should—due to its generality—be informative to techniques for meta-analysis.     

Chunking versus foraging search patterns by rats in the hierarchically baited radial maze

Rats were exposed to a radial maze containing six black smooth arms and six wire-grid-covered arms and a striped 'exit arm' in experiment 1. The probability of a black or grid arm being baited (5/6 vs 1/6) with sunflower seeds was associated with its proximal cue for some rats (the Relevant Arm Cue group) but not for others (the Irrelevant Arm Cue group). All rats could terminate a trial and receive a highly preferred morsel of apple by entering the exit arm only after having sampled all six seed-baited arms. Relevant Arm Cue rats usually chose some arms from the more densely baited set before choosing an arm from the less densely baited set and made fewer reentries than Irrelevant Arm Cue rats. Although such clustered, higher choice accuracy in the Relevant Arm Cue group corresponds to human clustered, better recall of verbal items from lists hierarchically organized by categories, these rats did not similarly exhaustively retrieve items (arm locations). That is, when required to terminate a trial by entering the 'exit' arm for an apple morsel after having sampled all seed-baited arms, both groups were equally unable to withhold making nonrewarded premature exits. This nonexhaustive foraging search pattern was maintained in the next two experiments in which the radial maze was reduced to three black and three grid arms along with the striped 'exit' arm and in which black and grid arm cues were paired with number of seeds (eight or one) in an arm for Relevant Arm Cue rats. Although Relevant Arm Cue rats displayed perfect clustering by entering all eight-seeded arms before a one-seeded arm, they made more premature exits and reentries into eight-seeded arms in experiment 2 or when forced to enter all eight-seeded arms in experiment 3 than did Irrelevant Arm Cue rats. These foraging tendencies prevent accurate estimations of the amount of information (i.e., arm locations) rats can 'chunk'. Electronic Publication     

Stochastic search item selection for factor analytic models

In this paper we implement a Markov chain Monte Carlo algorithm based on the stochastic search variable selection method of George and McCulloch (1993) for identifying promising subsets of manifest variables (items) for factor analysis models. The suggested algorithm is constructed by embedding in the usual factor analysis model a normal mixture prior for the model loadings with latent indicators used to identify not only which manifest variables should be included in the model but also how each manifest variable is associated with each factor. We further extend the suggested algorithm to allow for factor selection. We also develop a detailed procedure for the specification of the prior parameters values based on the practical significance of factor loadings using ideas from the original work of George and McCulloch (1993). A straightforward Gibbs sampler is used to simulate from the joint posterior distribution of all unknown parameters and the subset of variables with the highest posterior probability is selected. The proposed method is illustrated using real and simulated data sets.     

Presence of meaning,search for meaning,religiousness, satisfaction with life and depressive symptoms among a diverse Israeli sample

The present study explored the structure and correlates of meaning in life (MIL) among an Israeli sample. The sample consisted of 559 adults. The average age of participants was 48.24 and 61.3% of them were females. Participants provided demographic information and completed measures of MIL, satisfaction with life, and depressive symptoms. The MIL Questionnaire showed a very good fit for the proposed 2-factor model (i.e. presence of meaning, search for meaning) to the data collected from the current sample. Presence of meaning correlated positively with both search for meaning and satisfaction with life, and negatively with depressive symptoms. Search for meaning was positively and weakly tied to satisfaction with life, but was unrelated to depressive symptoms. Religiousness appeared as a significant moderator between the two meaning factors, and between them and life satisfaction. Specifically, as religiousness became stronger: (a) the link between presence of meaning and search for meaning became weaker; (b) the link between presence of meaning and life satisfaction became stronger and (c) the link between search for meaning and life satisfaction became weaker. The findings suggest that there are differential implications of presence search for meaning on the health and well-being, and the important role religiousness plays in this regard.     

Dialogue in Our Cosmic Aloneness

The search for extraterrestrial intelligence (SETI) is briefly summarized to serve as a background for making the case that, due to the highly exceptional characteristics of the earth's position and motion in the solar system as well as the precarious history of human evolution, we may be alone in the universe. With the conviction that this cosmic isolation enhances our need for dialogue with God, I discuss the nature of authentic dialogue as exhaustively explored by Martin Buber. I conclude with remarks dealing with the importance of understanding and using Buber's insights on dialogue as a way of satisfying our primal need to communicate with a cosmic “other,” in particular, God. Thus, in contrast to the numerous articles that have discussed the theological implications of SETI being successful, I treat here what it might mean if we are alone.     

Expertise in complex decision making: the role of search in chess 70 years after de Groot

One of the most influential studies in all expertise research is de Groot's (1946) study of chess players, which suggested that pattern recognition, rather than search, was the key determinant of expertise. Many changes have occurred in the chess world since de Groot's study, leading some authors to argue that the cognitive mechanisms underlying expertise have also changed. We decided to replicate de Groot's study to empirically test these claims and to examine whether the trends in the data have changed over time. Six Grandmasters, five International Masters, six Experts, and five Class A players completed the think-aloud procedure for two chess positions. Findings indicate that Grandmasters and International Masters search more quickly than Experts and Class A players, and that both groups today search substantially faster than players in previous studies. The findings, however, support de Groot's overall conclusions and are consistent with predictions made by pattern recognition models.     

Older children's misunderstanding of uncertain belief after passing the false belief test

A four-location belief task was designed to examine children's understanding of another's uncertain belief after passing a false belief (FB) task. In Experiment 1, after passing the FB task, participants were asked what a puppet would do after he failed to find his toy at the falsely believed location. Most 4-year-olds and half of 6-year-olds children who passed the FB test showed difficulty in handling uncertain belief; answering that the puppet would then look for his toy at the current (moved-to) location. Eight-year-old children and adults all recognized that the puppet would look for the toy everywhere, or at random. In Experiment 2, 4- and 6-year-olds were presented two other search tasks; it was shown that preschoolers could use search strategies to solve a similar search problem when FB was not involved. This new aspect of post-FB understanding can be interpreted in terms of limited understanding of uncertainty in a less-knowledgeable individual and of limited ability to infer the consequences of belief-disconfirmation.     

Effects of arm weight on C-not-B task performance: implications for the motor inhibitory deficit account of search failures

Toddlers have been found to fail on a three-location search task involving the invisible displacements of an object, namely the C-not-B task. In this task, a child is shown the experimenter's hand that contains a toy. The toy then successively disappears under the three cloths (A, B, then C). The examiner silently releases the toy under the second cloth (B). The hidden object makes a bump in the B cloth that covers it. Young children emit a strong bias toward the last cloth that the experimenter's hand passes under, and this has been labeled the C-not-B error. One possible explanation for toddlers' failures in the C-not-B task is that children lack the motor inhibitory mechanisms. To test this hypothesis, the robustness of the C-not-B error was tested, in a first experiment, against variations in body parameters. By putting additional weights on the arm, the C-not-B error was reduced substantially and the C-not-B task had a higher rate of success. Indeed, in contrast to control participants, who ignored a visual clue indicating the correct location of the hidden object and reached for the last location of the experimenter's hand, the participants with arm weights initiated their reaching movements by using the visual clue. The findings from the second control group indicate that the dramatic increase in successful performance by children with arm weights is not merely a consequence of the focus on the attention to arm movements. The motion of the experimenter's hand in space appears to have made the task difficult because toddlers had no problems inferring that a lump under a cloth indicates the existence of an object without actually having watched an object be hidden there, as demonstrated in a second experiment. The findings are consistent with the hypothesis that C-not-B task content activates a prepotent motor response that preempts full consideration of a visual clue indicating the correct location of the hidden object. We propose that the success in the C-not-B task of toddlers with additional arm weights could result from a disruption of automatic hand movement that is triggered by sensory signals, namely salient features of the C-not-B task.     

自我职业选择测验(SDS)的试用报告

本研究对自我职业选择测验 (SDS) 1 985年版进行了修订 ,并在武汉市中学生中进行了适用性的验证。在原测验中译本基础上 ,进行了项目修改、项目分析、信效度检验等标准化工作。结果表明 :①该测验具有良好的项目特性 ;②该测验同质性信度、分半信度均达到一般心理测验要求标准 ;③该测验结构效度与效标关联效度亦较为理想 ;④个别项目仍有待于进一步修改 ,取样还应面向全国 ,以利于进一步的推广作用。在武汉市中学生中的试用结果表明 :①该测验可以作为中学生职业辅导的选用工具 ;②在该测验中使用标准分代替粗分更具科学性。     

Age differences in what is viewed and remembered in complex conjunction search

Older and younger adults searched arrays of 12 unique real-world photographs for a specified object (e.g., a yellow drill) among distractors (e.g., yellow telephone, red drill, and green door). Eye-tracking data from 24 of 48 participants in each age group showed generally similar search patterns for the younger and older adults but there were some interesting differences. Older adults processed all the items in the arrays more slowly than the younger adults (e.g., they had longer fixation durations, gaze durations, and total times), but this difference was exaggerated for target items. We also found that older and younger adults differed in the sequence in which objects were searched, with younger adults fixating the target objects earlier in the trial than older adults. Despite the relatively longer fixation times on the targets (in comparison to the distractors) for older adults, a surprise visual recognition test revealed a sizeable age deficit for target memory but, importantly, no age differences for distractor memory.