Knowledge Acquisition and Conceptual Change

Dans cet article, je soutiens qu'il est fructueux de penser les réseaux conceptuels en termes de théorie et les processus d'acquisition des connaissances en termes d'articulation ou de restructuration de ces théories. La recherche que mes collègues et moi-même avons entreprise montre que la restructuration d'une connaissance antérieure se fait habituellement lentement et graduellement et qu'elle implique la réinterprétation de certaines croyances que les individus élaborent à partir de leur expérience quotidienne. Pour aider à la restructuration, une formation devrait faire prendre conscience aux étudiants de leurs convictions préétablies et leur proposer un cadre de référence différent en remplacement du celui qu'ils ont construit à partir de leur expérience personnelle.
In this paper I argue that it makes sense to think of conceptual structures as theories, and of the process of knowledge acquisition as the articulation or restructuring of these theories. The research that my colleagues and I have undertaken shows that the restructuring of prior knowledge is usually achieved in a slow and gradual fashion, and that it requires the reinterpretation of certain beliefs, which individuals construct on the basis of their everyday experience. In order to promote restructuring, instruction should aim at making students aware of their entrenched beliefs and at providing them with a different explanatory framework to replace the one they have constructed on the basis of their phenomenal experience.     

The effects of baby bath and massage by fathers on the family system: The sunraysia australia intervention project

Instruction in baby massage and the Burleigh Relaxation Bath technique was given to one-half of our sample of 32 couples who had just had their first child. This brief intervention, given at 4 weeks post-partum, led to beneficial behavioural and psychological effects for the family system when assessed at 12 weeks postpartum. Depression and marital satisfaction were assessed with mothers and fathers at 4 weeks and 12 weeks after the birth of their child, and self-esteem was measured at 12 weeks only. The mothers and fathers who were shown baby bathing and massage techniques showed higher degrees of marital satisfaction and self-esteem, as well as lower levels of depression at 12 weeks post-partum, than parents who did not receive instruction. It seems likely that brief interventions which educate new parents concerning functional techniques of baby care may favourably affect their feelings of competence and be of benefit to the entire family system.     

Instructional and probability manipulations of bias in multiletter matching

Ratcliff (1985) performed fits of his diffusion model to the results of multiletter-matching experiments conducted by Ratcliff and Hacker (1981) and Proctor, Rao, and Hurst (1984), in which bias to respond "same" or "different" was manipulated by instructions and probabilities, respectively. The fits showed that both bias manipulations affected settings of a goodness-of-match criterion, whereas instructions also affected sensitivity. Evaluations of the experimental procedures and of Ratcliff's model-fitting procedures were performed in the present study. Three experiments showed that instructions and probabilities had similar effects, regardless of whether the different pairs were blocked or randomized according to the number of mismatching positions. The most salient feature of the results--that "same" reaction times were traded off more than were "different" reaction times, with no corresponding asymmetry in the error rates--was evident in all situations. The evaluation of Ratcliff's model-fitting procedures indicated that the apparent influence of instructions on sensitivity likely is an artifact of unequal variance for the sets of same and different pairs. Moreover, the effects of bias can be explained in terms of settings of response criteria, rather than of the goodness-of-match criterion, as in Ratcliff's fits.     

A secondary-task analysis of a word familiarity effect

In three experiments we examined aspects of the word inferiority effect and word frequency disadvantage for letter detection. In Experiment 1 we tested a prediction derived from a hypothesis based solely on attentional factors. Adult subjects performed one of two secondary detection tasks while reading for comprehension. The inferiority effects were obtained only when the secondary task was letter detection, not when nonletter targets were used in the secondary task. This finding is inconsistent with the attentional hypothesis, but is consistent with the unitization hypothesis of Healy and Drewnowski (1983). In Experiments 2 and 3 we found that manipulation of the need to read for comprehension had little influence on the letter-detection inferiority effects, but a strong influence on the effects involving the detection of nonletter targets. These results are discussed in terms of their implications concerning processing system flexibility.     

A human-centered approach for designing World-Wide Web browsers

Because the World-Wide Web has features that are not found in traditional information systems, it has some unique problems pertaining to human use, such as the difficulty of searching for specific information. This paper describes human cognitive limitations pertinent to the design of Web browsers and provides a conceptual model for human information processing on the Web. It also compares user strategies and use of browser functions for two tasks that differ in the specificity of the information that is to be retrieved. General principles and specific recommendations for the design of Web browsers are derived from these considerations.     

Set- and Element-Level Stimulus-Response Compatibility Effects for Different Manual Response Sets

In a previous study of two-choice reactions, pairings of spatial stimuli with bimanual presses made on a keyboard and verbal stimuli with unimanual aimed movements made on a display screen showed higher set-level compatibility than the opposite pairings; element-level compatibility (i.e., mapping) effects were also larger for the conditions with high set-level compatibility than for those whose set-level compatibility was low. In the 4 experiments described here, the relevant factors were isolated, allowing the determinants of those compatibility differences to be evaluated in more detail. Forty-eight students participated in Experiment 1, and 24 each in Experiments 2, 3, and 4. The primary determinant of the set-level compatibility variation was whether the response alternatives involved 1 or 2 effectors, but the differences in element-level compatibility effects were determined primarily by the distinction between responding on the screen as opposed to on the keyboard. Implications for models of stimulus-response compatibility are examined.     

Mental models of the earth, sun, and moon: Indian children's cosmologies

This study reports data on the acquisition of knowledge about astronomy in children from India. Based on prior research, we hypothesized that the cosmological models that children construct are influenced by both first-order and second-order constraints on knowledge acquisition. First-order constraints are the implicit assumptions that govern the construction of initial cosmological models. Examples of such constraints include the assumptions that the earth is flat and supported. Such first-order constraints are presumed to be universal. Second-order constraints arise from the specific properties ascribed to cosmological objects. For example, representations of the earth's shape and location relative to the sun and moon constrain the kinds of mechanisms that are generated to account for the day-night cycle. We hypothesized that in cultures where both folk cosmologies and the scientific cosmological model are accessible to children, aspects of folk models are likely to be incorporated in children's cosmologies if they provide a psychologically easier way of satisfying first-order constraints. This hypothesis is supported by our findings with regard to universality and culture specificity in children's cosmologies. Indian children's cosmologies honor a variety of universal first-order constraints. These include constraints on the shape of the earth (e.g., support and flatness) and on the relative locations and motions of objects in the cosmology (e.g., continuity). However, many Indian children borrow the idea that the earth is supported by an ocean or a body of water from folk cosmology. This solution to the support constraint on the shape of the earth is not found in American children's initial cosmologies.     

Recognition memory for pictures as a function of poststimulus interval: an empirical clarification of existing literature

Shaffer and Shiffrin (1972) found no effect of the duration of a blank poststimulus interval on recognition memory for visual scenes. The majority of subsequent studies, however, have found a positive relationship between interval duration and recognition accuracy. The present experiments were conducted to clarify these contradictory outcomes. Experiment 1 determined that Shaffer and Shiffrin's results are replicable with the method that they used in which stimulus durations and poststimulus-interval durations vary randomly within the study list. Experiments 2-3 showed that this random intermixing of durations is the critical factor that results in poststimulus interval having no effect. The results were interpreted in terms of a voluntary rehearsal process that is abandoned when there is uncertainty regarding the time of onset and offset of the stimuli.     

The influence of metacontrast masking on detection and spatial-choice judgments: an apparent distinction between automatic and attentive response mechanisms

Several studies of metacontrast masking in the 1960s apparently showed that the latency of simple detection responses was uninfluenced by the phenomenal dimming of the target induced by the mask. More recent studies using more suitable methodologies have clearly shown that such is not the case for situations in which the masking is a monotonically decreasing function of stimulus onset asynchrony. Experiment 1 investigated this issue for the situation in which masking is a U-shaped function of stimulus onset asynchrony. Contrary to the results obtained in monotonic masking situations, simple detection responses were not slowed by the masking. Experiment 2 demonstrated that although detection responses are not slowed in the U-shaped masking situation, spatial-choice judgments are. Experiments 3 and 4 indicated that this masking effect on spatial-choice reaction time is lost relatively rapidly with practice. However, changing the stimulus-response assignments reinstates the effect. The experiments suggest that for the situation in which U-shaped masking functions are obtained, responses that require attention (spatial-choice judgments early in practice or after stimulus-response relationships have been switched) are influenced by the metacontrast-induced phenomenal dimming, whereas responses that are automatic (i.e., detection responses; practiced spatial-choice judgments with consistent stimulus-response mappings) are not.     

Drawing inferences from semantically positive and negative implicative predicates

Subjects were timed while they drew inferences from syntactically affirmative and negative sentences containing the semantically positive and negative implicative predicates remember/forget and bother/neglect, under different linguistic contexts that met the presuppositions of the sentences at varying levels of generality. Different patterns of inference latencies were obtained for the two implicative predicates studied, suggesting that there are important differences among semantically negative implicative predicates that influence their representation and processing. Regardless of these differences, inference latencies for all sentences decreased when they were presented in contexts that met some of their presuppositions, indicating that context can facilitate inferential processing.