The conjunction fallacy: A test of averaging hypotheses

The conjunction fallacy, in which individuals report that the conjunction of two events is more rather than less likely to occur than one of the events alone, is a robust phenomenon. We assessed the possibility that an analysis in terms of functional measurement methodology might be consistent with occurrence of the fallacy. A 3 × 3 design in which we varied the judged likelihood of the two components constituting the conjunction permitted us to assess the possibility that subjects judge the likelihood of conjunctions by averaging the likelihood of their component parts. The results were consistent with this possibility, and this interpretation was supported by analysis of the results in terms of functional measurement methodology.     

The revelation effect: A meta-analytic test of hypotheses

Judgments can depend on the activity directly preceding them. An example is the revelation effect whereby participants are more likely to claim that a stimulus is familiar after a preceding task, such as solving an anagram, than without a preceding task. We test conflicting predictions of four revelation-effect hypotheses in a meta-analysis of 26 years of revelation-effect research. The hypotheses’ predictions refer to three subject areas: (1) the basis of judgments that are subject to the revelation effect (recollection vs. familiarity vs. fluency), (2) the degree of similarity between the task and test item, and (3) the difficulty of the preceding task. We use a hierarchical multivariate meta-analysis to account for dependent effect sizes and variance in experimental procedures. We test the revelation-effect hypotheses with a model selection procedure, where each model corresponds to a prediction of a revelation-effect hypothesis. We further quantify the amount of evidence for one model compared to another with Bayes factors. The results of this analysis suggest that none of the extant revelation-effect hypotheses can fully account for the data. The general vagueness of revelation-effect hypotheses and the scarcity of data were the major limiting factors in our analyses, emphasizing the need for formalized theories and further research into the puzzling revelation effect.     

Gender and reward distributions: A test of two hypotheses

This study was designed as a test of two competing explanations of gender differences in distributive justice: (a) the equity-equality hypothesis, which states that males endorse equitable distributions more than females and females endorse equal distributions more than males; and (b) the exploitation-accommodation hypothesis, which states that the sexes vary their norm endorsement according to self-favoring (males) or other-favoring (females) distribution outcomes. Preadolescent and college-aged subjects rated the fairness of reward distributions of vignette characters who had contributed either more or less than a co-worker in a task, and had subsequently divided the rewards either equitably or equally. The data provided no support for the equity-equality hypothesis, but did support the exploitation-accommodation hypothesis. Specifically, females rated equitable distributions of inferior workers as more fair than males did. Thus, the popular conclusion that males have a stronger commitment to equity than females must be rejected.     

Serial learning in rats: A test of three hypotheses

Findings obtained by providing rats with a single fixed series of events, A-B-C-…, often are equally compatible with three alternative serial learning interpretations: that the signal for items is (A) their position in the series (position view), (B) the prior item of the series (chaining view), and (C) one, two, or more prior items of the series (sequential view). By employing a novel procedure of supplying rats with two different series, rather than a single series, it was possible to choose between the three alternatives. Employing 10 and 0, 0.045 g, Noyes pellets as items, rats in both runway experiments reported here received a three trial series, either a 10-0-10 series or a 0-0-10 series. In Experiment 1, the other series was a single 0 pellet trial (along with 10-0-10) or a single 10 pellet trial (along with 0-0-10). In Experiment 2, the other series was either 0-0 (along with 10-0-10) or 10-0 (along with 0-0-10). Considering both experiments, findings were consistent with the sequential view but not with either the position view or the chaining view. The possibility was suggested that, under some other experimental conditions, particularly those not employing reward events as items, greater control over discriminative responding might be exercised by position cues than by item cues.     

A test of size-scaling and relative-size hypotheses for the moon illusion

In two experiments participants reproduced the size of the moon in pictorial scenes under two conditions: when the scene element was normally oriented, producing a depth gradient like a floor, or when the scene element was inverted, producing a depth gradient like a ceiling. Target moons were located near to or far from the scene element. Consistent with size constancy scaling, the illusion reversed when the "floor" of a pictorial scene was inverted to represent a "ceiling." Relative size contrast predicted a reduction or increase in the illusion with no change in direction. The relation between pictorial and natural moon illusions is discussed.     

A multipurpose four-dimensional analysis of variance program

A computer program is described for a four-dimensional analysis of variance using the IBM 360/40 OS, or larger, machine.     

A jackknife test of homogeneity of variance with paired replicates data

A nonparametric test of dispersion with paired replicates data is described which involves jackknifing logarithmic transformations of the ratio of variance estimates for the pre- and post-treatment populations. Results from a Monte Carlo simulation show that the test performs well underH _o and has good power properties. Examples are given of applying the procedure on psychiatric data.A referee called our attention to valuable references which related to our work, and he suggested the inclusion of competing jackknife procedures into our studies.     

A simple test for heterogeneity of variance in complex factorial designs

A simple procedure for testing heterogeneity of variance is developed which generalizes readily to complex, multi-factor experimental designs. Monte Carlo Studies indicate that the Z-variance test statistic presented here yields results equivalent to other familiar tests for heterogeneity of variance in simple one-way designs where comparisons are feasible. The primary advantage of the Z-variance test is in the analysis of factorial effects on sample variances in more complex designs. An example involving a three-way factorial design is presented.     

An experimental test of three choice shift hypotheses*

The present experiment pitted three choice shift hypotheses against each other in an attempt to eliminate one or more of the hypotheses and find support for those remaining. Ss responded three times to the 12 CDQ items, once as a pretest and twice following presentation of homogeneous sets of three arguments which advocated either a risky or a cautious position. The risk-as-value, relevant arguments, and conformity/attitude change hypotheses generated three separate predictions for the Ss' responses. Results mirrored the prediction of the relevant arguments hypothesis: New information, whether contained in cautious or risky arguments, caused a shift toward the type of argument presented. The risk-as-value and the conformity/attitude change hypotheses could not explain the present data.