Estimation of the hypothesis hierarchy in probabilistic inference tasks*

Is there a hierarchical order among the hypotheses about functional rules in probabilistic inference tasks, i.e. what is the construction and the procedure of the “hypothesis sampling mechanism” employed by the subjects in this kind of task? According to the hypothesis sampling model initially proposed by Brehmer (1974) there should be a hierarchical order among the hypotheses in the subject's hypothesis pools. The procedures of hypothesis sampling and testing ought to follow this strict data independent order (see e.g. Sniezek, 1986; Brehmer, 1987). Knez (1991a, b) showed, however, that this assumption may be incorrect. As a follow up to these results the question regarding the construction of the subject's hypothesis pools was reapproached in the present study. The results indicated a consistency with the hierarchical assumption (Brehmer, 1974) only regarding the relation between the linear and nonlinear rules but not within these types of rules.     

RITUAL, TIME, AND ENTERNITY

Abstract. It is argued here that the construction of time and eternity are among ritual's entailments. In dividing continuous duration into distinct periods ritual distinguishes two temporal conditions: (1) that prevailing in mundane periods and (2) that prevailing during the intervals between them. Differences in the frequency, length, and relationship among the rituals constituting different liturgical orders are considered, as are differences between mundane periods and ritual's intervals with respect to social relations, cognitive modes, meaningfulness, and typical interactive frequencies. Periods, it is observed, relate to intervals as everchanging to never-changing, and close relationships of never changing to eternity, eternity to sanctity, and sanctity to truth are proposed. In the argument that ritual's "times out of time" really are outside mundane time, similarities to the operations of digital computers and Herbert Simon's discussion of interaction frequencies in the organization of matter are noted.     

Perceptual Learning

The extent of adult improvement in not only complex but also simple perceptual tasks is remarkable. Although this phenomenon has been noted and studied since the middle of the 19th century, recent advances in the study of brain physiology and anatomy afford new insights. Improvement specificity suggests that changes involve early sensory cortical areas, previously thought to lose their plasticity following the first years. The critical role of selective attention, even in learning the simplest tasks, as well as the precedence of learning easy cases, suggests the involvement of high-level cortical areas. Learning easy cases is more general than learning difficult cases. This pattern suggests the involvement of both high- and low-level areas in an orderly manner, with easy learning beginning at high-level areas and harder cases being resolved by access to low-level areas. The mapping of behavioral findings to underlying brain sites provides a unified framework for this interdisciplinary field.     

The Dream of Consensus: Finding Common Ground in a Bioethical Context

Consensus is the holy grail of bioethics, the lynch pin of the assumption that well informed, well intentioned people may reach generally acceptable positions on ethically contentious issues. It has been especially important in bioethics, where advancing technology has assured an increasing field of complex medical dilemmas. This paper results on the use of a multicriterion decision making system (MCDM) analyzing group process in an attempt to better define hospital policy. In a pilot program at The Hospital for Sick Children, Toronto, a series of small scale focus groups was constituted to examine criteria defining organ transplant eligibility. Criteria were organized hierarchically using the Analytic Hierarchy Process, an MCDM approach, and the resulting data was analyzed using Expert Choice 9.0, software designed to facilitate AHP analysis. Qualitative and quantitative analysis map barriers to practical consensus in a way not previously possible.     

Uncertainty about the rest of the sentence

A word-by-word human sentence processing complexity metric is presented. This metric formalizes the intuition that comprehenders have more trouble on words contributing larger amounts of information about the syntactic structure of the sentence as a whole. The formalization is in terms of the conditional entropy of grammatical continuations, given the words that have been heard so far. To calculate the predictions of this metric, Wilson and Carroll's (1954) original entropy reduction idea is extended to infinite languages. This is demonstrated with a mildly context-sensitive language that includes relative clauses formed on a variety of grammatical relations across the Accessibility Hierarchy of Keenan and Comrie (1977). Predictions are derived that correlate significantly with repetition accuracy results obtained in a sentence-memory experiment (Keenan & Hawkins, 1987).     

Occupational violence: Armed holdup—A risk management approach

Workplace violence covers a wide spectrum of incidents of aggression that may occur at work. One area of particular concern relates to holdups. This study reviewed all incidents of robbery (holdups and bag snatches) occurring in a quasi-government wagering organization throughout Queensland, Australia between 1990 and August 1993. The study covered 30 robberies, at 28 sites with 34 subjects, 22 of whom consented to complete a questionnaire related to the stressfulness and impact of the event. Most robberies occurred at opening or closing time, at sites situated on a main thoroughfare, predominantly on a Monday. Single males (n =15) or a pair (n =15) mostly carrying a gun were the perpetrators. Nineteen of the 22 victims attended critical incident debriefing and most found this valuable. Only one subject interviewed lost time for stress (and this was the fourth time she had been robbed). One subject not interviewed was hospitalized. Other subjects had minor physical injuries, but suffered emotionally for up to a year after the incident. Recommendations focused on the hierarchy of control (environmental and engineering controls in preference to people-focused change). Additionally training in the normal processes of grief and trauma was recommended.     

Identification and modification of a response-class hierarchy

We evaluated the effects of extinction and negative reinforcement on the latency of response-class members following requests made to a 15-year-old female with moderate mental retardation and autism. A functional analysis showed that the class members (screams, aggression, and self-injury) were escape maintained. Informal observations suggested that these topographies generally occurred in the sequence listed above and therefore may have been hierarchically related. A therapist provided escape from demands contingent on a specific member of the class to determine the effects on the latency of the members' occurrence. Results showed that the latencies occurred in a predictable order. In addition, we expanded the response class to include a vocal response that was functionally equivalent to other members. Findings are discussed regarding the covariation and sequence of response-class members and treatment development.     

DISCRIMINATION TRAINING FOR PERSONS WITH DEVELOPMENTAL DISABILITIES: A COMPARISON OF THE TASK DEMONSTRATION MODEL AND THE STANDARD PROMPTING HIERARCHY

A comparison was made between two procedures for teaching persons with severe handicaps: (a) the task demonstration model, which is based upon a fading procedure and general case programming, and (b) the standard prompting hierarchy, a least-to-most intrusive prompting procedure commonly used to teach these individuals. Five phases were used in comparing the procedures: pretesting, training, two generalization tests, and a 6-month maintenance test. Eight students learned two discrimination tasks by each procedure, with each task involving two- or three-digit numbers. Results showed that under the task demonstration model all 8 subjects had more unprompted correct responses (about 1.5 times as many) in training, all 8 subjects had fewer errors (about 0.6 times as many) in training, all 8 subjects had more correct responding in the generalization test with untrained stimuli in the training room, 6 of 8 subjects had more correct responding with untrained stimuli in another room, a 7th had equivalent amounts, and 7 of 8 subjects had more correct responding on a 6-month maintenance test. Thus, the task demonstration model proved superior to the standard prompting hierarchy in 29 of 32 tests of correct responding. Results are discussed in terms of implications for stimulus control training strategies.     

A COMPARISON OF TIME DELAY AND DECREASING PROMPT HIERARCHY STRATEGIES IN TEACHING BANKING SKILLS TO STUDENTS WITH MODERATE HANDICAPS

Four students with moderate handicaps were taught to cash checks and to use an automatic teller through either a decreasing prompt hierarchy or time delay procedure. The strategies were compared within a multielement design. Results indicated that both strategies led to the acquisition of the target tasks; however, the decreasing prompt hierarchy was more efficient. Four and 8-week follow-up probes indicated that the strategies were equally effective in producing maintenance of performance.     

内隐学习中表征与意识的关系

近年来研究者分别从表征的质量和表征的外显等级两个方面探讨了内隐学习中表征与意识的关系。有关表征质量与意识的研究,清晰地揭示了影响表征进入意识的因素;而有关表征外显等级与意识的研究,则明确地阐明了什么样的表征才是有意识的。但表征与意识的关系是一个十分复杂的问题,目前仍存在着很大的争议,还有待于进一步的探讨