Biomedical subjects

S A Sloman

Publications and source records attributed to S A Sloman.

3 recordsLinked to original sources

PubMed1994

When explanations compete: the role of explanatory coherence on judgements of likelihood.

The likelihood of a statement is often derived by generating an explanation for it and evaluating the plausibility of the explanation. The explanation discounting principle states that people tend to focus on a single explanation; alternative explanations compete with the effect of reducing one another's credibility. Two experiments tested the hypothesis that this principle applies to inductive inferences concerning the properties of everyday categories. In both experiments, subjects estimated the probability of a series of statements (conclusions) and the conditional probabilities of those conclusions given other related facts. For example, given that most lawyers make good sales people, what is the probability that most psychologists make good sales people? The results showed that when the fact and the conclusion had the same explanation the fact increased people's willingness to believe the conclusion, but when they had different explanations the fact decreased the conclusion's credibility. This decrease is attributed to explanation discounting; the explanation for the fact had the effect of reducing the plausibility of the explanation for the conclusion.

Cognition↗

PubMed1994

Similarity- versus rule-based categorization.

An influential study by Rips (1989) provides the strongest evidence available that categorization cannot be reduced to similarity. In Rips's study, subjects were presented a sparse description of an object that mentioned only a value on a single dimension (e.g., "an object 3 inches in diameter"), followed by two categories (e.g., pizza and quarter), where one allowed more variability on the relevant dimension than did the other (the diameter of pizzas is more variable than that of quarters). Subjects judged the described object to be more likely to be a member of the variable category (pizza), but more similar to the nonvariable category (quarter). This dissociation between categorization and similarity strongly implies that categorization was not based on similarity. In our first experiment, we used sparse descriptions like Rips's, as well as rich descriptions that contained features characteristic of the nonvariable category. We found that categorization tracked similarity with both kinds of descriptions. In a second experiment, we modified our procedure to be more like that of Rips's by requiring subjects to think aloud while making their decisions. Now, like Rips, we found a dissociation between similarity and categorization with sparse items; with rich descriptions, categorization again tracked similarity. These findings are consistent with the hypothesis that categorization can be done in two ways, by similarity and by rule. An exclusive reliance on rule-based categorization seems to occur only when the description of the to-be-categorized object does not contain any features characteristic of any relevant category.

Adult↗

PubMed1991

Congruency effects in part-list cuing inhibition.

In demonstrations of part-list cuing inhibition, subjects who are shown a subset of studied list words recall fewer noncue words than subjects not shown such part-list cues. We propose that part-list inhibition is governed in part by an incongruency principle: Inhibition occurs to the extent that part-list cues induce a retrieval framework different from that used to encode list items. In Experiment 1, word lists were studied followed by a test of free recall either without cues, or with cue words serially organized to be either congruent or incongruent with the order of studied items. In Experiments 2-4, cues consisted of every second study item in the original presentation order (congruent ones) or reordered to form famous names or familiar idioms that had been hidden in the study list (incongruent cues). More part-list inhibition was observed with incongruent cues than congruent cues in all 4 experiments.

Analysis of Variance↗