Rule transition on the balance scale task: a case study in belief change

For various domains in proportional reasoning cognitive development is characterized as a progression through a series of increasingly complex rules. A multiplicative relationship between two task features, such as weight and distance information of blocks placed at both sides of the fulcrum of a balance scale, appears difficult to discover. During development, children change their beliefs about the balance scale several times: from a focus on the weight dimension (Rule I) to occasionally considering the distance dimension (Rule II), guessing (Rule III), and applying multiplication (Rule IV; Siegler, 1981). Because of the detailed empirical findings the balance scale task has become a benchmark task for computational models of proportional reasoning. In this article, we present a large empirical study (N = 420) of which the findings provide a challenge for computational models. The effect of feedback and the effect of individually adapted training items on rule transition were tested for children using Rule I or Rule II. Presenting adapted training items initiates belief revision for Rule I but not for Rule II. The experience of making mistakes (by providing feedback) induces a change for both Rule I and Rule II. However, a delayed posttest shows that these changes are preserved after 2 weeks only for children using Rule I. We conclude that the transition from Rule I to Rule II differs from the transition from Rule II to a more complex rule. Concerning these empirical findings, we will review performance of computational models and the implications for a future belief revision model.

It is one Thing, to show a Man that he is in an Error, and another, to put him in possession of Truth. John Locke

     

358,534 nonwords: The ARC Nonword Database

The authors present a model of the phonotactic and orthographic constraints of Australian and Standard Southern British English monosyllables. This model is used as the basis for a web-based psycholinguistic resource, the ARC Nonword Database, which contains 358,534 monosyllabic nonwords--48,534 pseudohomophones and 310,000 non-pseudohomophonic nonwords. Items can be selected from the ARC Nonword Database on the basis of a wide variety of properties known or suspected to be of theoretical importance for the investigation of reading.     

Are there lexicons?

Many models of the processing of printed or spoken words or objects or faces propose that systems of local representations of the forms of such stimuli—lexicons—exist. This is denied by partisans of the distributed-representation connectionist approach to cognitive modelling. An experimental paradigm of key theoretical importance here is lexical decision and its analogue in the domain of objects, object decision. How does each theoretical camp account for our ability to perform these two tasks? The localists say that the tasks are done by matching or failing to match a stimulus to a local representation in a lexicon. Advocates of distributed representations often do not seek to explain these two tasks; however, when they do, they propose that patterns of activation evoked in a semantic system can be used to discriminate between words and nonwords, or between real objects and false objects. Therefore the distributed-representation account of lexical and object decision tasks predicts that performance on these tasks can never be normal in patients with an impaired semantic system, nor in patients who cannot access semantics normally from the stimulus domain being tested. However, numerous such patients have been reported in the literature, indicating that semantic access is not needed for normal performance on these tasks. Such results support the localist form of modelling rather than the distributed-representation approach.     

Bargaining strength and group polarization in intergroup negotiations

In the context of a labour-management simulation study, three-man union teams were made to believe that they had either a very strong or a very weak bargaining position vis-à-vis the other party. In half of each of these conditions, a cooperative and a competitive orientation toward the other group was induced. In preparation for the intergroup negotiations, the subjects were first asked to indicate their individual aspirations for three negotiation issues. After a group discussion, their collective aspirations were obtained. Regardless of the experimental conditions. groups set significantly higher aspiration levels than individuals on the most important issue but were more conservative and cautious on less important issues. In general, for all three topics, significant or near-significant interactions were found between bargaining strength and the direction of the group-induced shift. In the strong bargaining condition, groups set higher aspiration levels than the average of prior individual judgments; in the weak bargaining condition the opposite trend occurred. An effort was made to relate these findings to the various theories developed in the ‘risky-shift’ literature.     

Evidence for an integration theory of visual masking

When letters are superimposed upon a pattern of black and white squares, they are easier to identify when the pattern is regular than when it is random. If backward masking consists of the superimposition of a masking pattern upon the decaying visual trace of a target display, a regular pattern should be less effective as a backward mask than a random pattern. This was found to be so for both multiple-letter and single-letter displays. This result is predicted by an integration theory of visual masking but not by an interruption theory.     

Short-term recognition memory for pitch: Effect of a priori probability on response times and error rates

A previous finding (Bindra, Williams, & Wise, 1965) that Ss respond “different” more quickly than “same” when comparing the pitch of two tones was confirmed. It was found that this effect could be enhanced by making same trials less frequent and that the effect could be reversed by making same trials more frequent. The experimental treatment also affected the error rates of the two responses. Error and latency results are discussed in terms of a model of R T based upon a sequential-sampling and decision procedure, and are shown to be compatible with such a model. A decision bias towards the response “different” must be taken into account when the model is applied. This bias appears to be influenced by the size of the interstimulus interval used.