Audience Design in Multiparty Conversation

How do speakers design what they say in order to communicate effectively with groups of addressees who vary in their background knowledge of the topic at hand? Prior findings indicate that when a speaker addresses a pair of listeners with discrepant knowledge, that speakers Aim Low, designing their utterances for the least knowledgeable of the two addressees. Here, we test the hypothesis that speakers will depart from an Aim Low approach in order to efficiently communicate with larger groups of interacting partners. Further, we ask whether the cognitive demands of tracking multiple conversational partners' perspectives places limitations on successful audience design. We find that speakers can successfully track information about what up to four of their partners do and do not know in conversation. When addressing groups of 3–4 addressees at once, speakers design language based on the combined knowledge of the group. These findings point to an audience design process that simultaneously represents the perspectives of multiple other individuals and combines these representations in order to design utterances that strike a balance between the different needs of the individuals within the group.     

Measurement of activity in small animals using a microcomputer-controlled system

A computer-controlled system that detects spontaneous activity (locomotion and rearing) and diurnal activity rhythms in small animals is described. Automatic recording of subtotals during test periods provides data about habituation (nonassociative learning). The system is relatively inexpensive to construct. Fabricated from highly reliable circuit components, it provides replicable measures that enable comparisons between different experimental treatments to be made using parametric statistics.     

Consensus at zero acquaintance: replication, behavioral cues, and stability.

That observers tend to agree in their ratings of a target even if they have never interacted with that target has been called consensus at zero acquaintance. The basic finding that consensus is highest for judgments concerning a target's degree of extraversion (EV) and somewhat weaker for judgments of conscientiousness is replicated. Several potential observable cues that might be used by judges when rating targets are examined. The finding that ratings of physical attractiveness correlate with judgments of EV is replicated. In Study 1, rapid body movements and smiling were also found to correlate with EV judgments. The level of consensus declined when initially unacquainted Ss interacted one-on-one (Study 2), but did not decline--and even increased--when Ss interacted in a group (Study 3). Ss judged as extraverted at zero acquaintance were also seen as extraverted after interacting with others.     

Constructing the exact significance level for a person fit statistic

This paper uses an extension of the network algorithm originally introduced by Mehta and Patel to construct exact tail probabilities for testing the general hypothesis that item responses are distributed according to the Rasch model. By assuming that item difficulties are known, the algorithm is applicable to the statistical tests either given the maximum likelihood ability estimate or conditioned on the total score. A simulation study indicates that the network algorithm is an efficient tool for computing the significance level of a person fit statistic based on test lengths of 30 items or less.     

Robust interactive decision-analysis (RID): Behavioral results and implications

We have proposed a novel interactive procedure for performing decision analysis, called Robust Interactive Decision Analysis (RID), which permits a decision maker (DM) to voluntarily and interactively express strong (viz, sure) binary preferences for actions, partial decision functions, and full decision functions, and only imprecise probability and utility function assessments. These serve as INPUTS TO operators to prune the state probability space and decision space until an optimal choice strategy is obtained. The viability of the RID approach depends on a DM's ability to provide such information consistently and meaningfully. On a limited scale we experimentally investigate the behavioral implications of the RID method in order to ascertain its potential operational feasibility and viability. More specifically, we examine whether a DM can (1) express strong preferences between pairs of vectors of unconditional and conditional payoffs or utilities consistently; (2) provide imprecise (ordinal and interval) state probabilities that are individually as well as mutually consistent with the state probabilities imputed from the expressed strong preferences. The results show that a DM can provide strong individually and mutually consistent preference and ordinal probability information. Moreover, most individuals also appear to be able to provide interval probabilities that are individually and mutually consistent with their strong preference inputs. However, the several violations observed, our small sample size, and the limited scope of our investigation suggest that further experimentation is needed to determine whether and/or how such inputs should be elicited. Overall, the results indicate that the RID method is behaviorally viable.     

Human interventions in a behavioural experiment for Asian Elephants (Elephas maximus)

Animal Cognition - Experiments are widely used to investigate the behaviour and cognition of animals. While the automation of experiments to avoid potential experimenter bias is sometimes possible,...     

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.     

Form symbolism, analogy, and metaphor

Simple forms, such as a square and a circle, can be symbolic; for example, a square can be deemed to behard and a circle to besoft. The relation between form symbolism and the comprehension of metaphors and analogies was studied in three experiments. Subjects were asked to rate matches between terms such assoft andhard andcircle andsquare as symbols (Experiment 1), metaphors (Experiment 2), and analogies (Experiment 3). The results show that a highly rated symbolic relation could be a poorly rated metaphorical relation. Ratings of analogies were similar to ratings of symbols. We argue that apt metaphors, analogies, and symbolic forms claim that the vehicle and the topic of the comparisons have common features, but that metaphoric representation entails more common features than does either symbolism or analogy, because metaphor requires that the vehicle be an especially apt example of a superordinate class. Thus, metaphor is a particularly strong claim about common features shared by the topic and the vehicle.     

Can Planck's constant be measured with classical mechanics?

An interesting case of the complex interaction between theory and experiment can be found in many experiments in quantum physics employing classical reasoning. It is expected that this practice would lead to quantitative inaccuracy, unless the measurements’ results were averaged. Whether or not this inaccuracy is significant depends critically on the details of the particular experimental situation. The example of Millikan's photoelectric experiment, in which he obtained a precise value of Planck's constant, provides a good case for illustrating the process of estimating the inaccuracy resulting from the classical‐quantum discrepancy. In the case of Millikan's experiment, it seems that a significant inaccuracy was avoided because of fortunate coincidences. In general, in the absence of a careful analysis, it is impossible to say whether the use of classical reasoning interferes with the accuracy of a quantum‐physical experiment.