Bias produced by fast guessing in distribution-based tests of race models

A comparison involving cumulative probability distributions of reaction time (RT) has been used to test race models of the redundancy gain observed in certain divided-attention paradigms. It has beenpointed out, however, that the presence of fast guesses wouldinterfera with this test, biasing it to accept race models. The present paper reports simulations carried out to determine the size of the bias introduced by fast guesses. In absolute terms, this bias can be quite large— exceeding 175 msec in some conditions. Simulations indicate that the bias increases with the percentage of fast guesses and with the latency difference between the lower tails of guess and nonguess RT distributions. Discarding and rerunning errors reduces bias somewhat, but a more elaborate “kill-the-twin” procedure reduces it much more.     

Crisis, taboos and careers guidance

The relevance of the idea of 'crisis' for careers and careers guidance is examined, together with some of the critical responses that have been made to recent crises. It is argued that careers guidance generally responds to such challenges by seeing them as external problems rather than as changes which may alter its very assumptions and methods. Two particular taboos are noted in this context concerning the value of work and of working for an organisation. The questioning of these taboos leads to four models of alternative careers: the Uncareer, the Guerilla Career, the Cop-Out Career, and the Non-Career. These forms of career raise the broader issues of order and disorder within careers, with their associated implications for careers guidance.     

Acquisition and retention of control of instrumental behavior by a cue-signaling airblast: How specific are conditioned anticipations?

The conditioned state evoked by a CS that had been paired with an aversive airblast was assessed by superimposing the CS on baselines of instrumental responding. The first experiment used a shock avoidance baseline; CS-airblast pairings were administered on the baseline, with the shock avoidance schedule in effect. The CS that signaled airblast came, over trails, to accelerate shock avoidance responding. As further CS-airblast trials were administered, however, the acceleratory effect of the CS decreased, producing an inverted-U-shaped acquisition curve. A second experiment used off-baseline CS-airblast conditioning, and the CS was tested on both shock avoidance and water reinforcement baselines. After 20 CS-airblast pairings the CS accelerated shock avoidance and suppressed water-reinforced responding. After 10o pairings, however, the acceleratory effect on shock avoidance was much attenuated, although the suppressions of the water-reinforced behavior did not differ between 20- and 100-trial groups. Two further experiments examined retention, over a 45-day interval, of the attenuation of the CS's effects on shock avoidance. Over the retention interval, this attenuation disappeared. It was, however, reinstated by giving the animals “reminder” presentations of the airblast. These results are interpreted as representing systematic changes in the specificity of the conditioned state evoked by a Pavlovian CS.     

Group performance as a function of group type,task condition and scholastic level

Studied performance on a multiple-solution anagrams task by two-member nominal, pseudo, quasi, and real groups in relation to task conditions (set versus nonset) and school grades (10th, 11th, and 12th). Nominal groups were made up of individuals working alone. Pseudo groups were made up of members sitting together but working independently for individual scores. Quasi groups were made up of members who were working together for a common or shared goal but were not allowed to communicate with each other. Real groups were the usual teams of freely interacting and mutually consulting members. Five words were presented to the subjects in the set condition (unlike in the nonset co ndition) in order to channelize their problem-solving activity in particular directions. The subjects were 192 male American high school students. The most important finding was that both nominal and pseudo groups produced more errors than real groups. Also the set condition generated more errors than the nonset condition. These and other findings were discussed and interpreted in the context of previous research.     

Perceived difficulty,energization, and the magnitude of goal valence

This paper examines the proposition that the mobilization of energy and consequent magnitude of valence of a potential outcome (e.g., goal) is a function of what the individual perceives can and must be done in order to attain or avoid the outcome. An outcome that is difficult to attain or avoid requires a relatively high level of energization and will be relatively attractive, if positive, or unpleasant, if negative. Outcomes that are easy or impossible to attain or avoid require little or no energization and will be relatively low in attractiveness, if positive, or low in unpleasantness, if negative. This formulation was supported by four experiments that demonstrated (a) attractiveness of a goal is a nonmonotonic function of perceived difficulty of attaining it; (b) unpleasantness of a potential negative outcome is a nonmonotonic function of perceived difficulty of avoiding it; (c) the nonmonotonic effect of perceived difficulty on goal attractiveness disappears once instrumental behavior has been completed; and (d) the nonmonotonic effect of perceived difficulty on unpleasantness of a potential negative outcome occurs in immediate but not distant anticipation of initiating instrumental behavior. Alternative explanations, theoretical problems, and implications are discussed.     

Children''s ability to make transitive inferences: The importance of premise integration and structural complexity

Four experiments investigated 4- to 6-year-olds' transitive inferences. In Experiments 1–3, there was a nonmapping condition in which inferences were made either about stacked blocks, or about sticks ordered left to right. In the mapping condition, inferences were made by mapping either from blocks to sticks, or the reverse. In Experiments 2–4, relational complexity was manipulated by requiring either 1 or 2 premise relations to be processed in a single decision. Mapping was harder than nonmapping, but relational complexity was the main source of variance, with 2 relations being harder in both mapping and nonmapping conditions. The percentage of participants integrating 2 relations in a single decision was estimated at 20% at age 4, 53% at age 5 and 57% at age 6, suggesting gradual development of transitive inference ability. Results suggest that relational complexity has a strong effect on transitive inference in 4- to 6-year-old children.     

Bivar: A program for generating correlated random numbers

This article describes Bivar, a program that generates random numbers from a wide variety of bivariate distributions. Numbers are written to an ASCII output file, from which they can be read as needed by programs simulating stochastic processes. The program runs under the DOS operating system on IBM-PC compatibles with a 386 or later processor, and it is free for educational and noncommercial use.     

The asynchronous discrete coding model: Further tests with single-attribute stimuli

Two experiments using a probe-RT paradigm showed that partial information about the size of a stimulus can influence response processes before complete size information is available. Contrary to the asynchronous discrete coding model, these results suggest that the perceptual system may transmit to the response system information that only partially specifies a single stimulus attribute. In combination with previous findings, these results also suggest that there are at least two dissociable forms of selective preparation for a given response.