Mental models of the earth: A study of conceptual change in childhood

This paper presents the results of an experiment which investigated elementary school children's conceptual knowledge about the earth. First-, 3rd-, and 5th- grade children were asked a series of questions about the shape of the earth. Children's responses to these questions revealed considerable apparent inconsistency. For example, many children said that the earth is round but also stated that it has an end or edge from which people could fall. A great deal of this apparent inconsistency could be explained by assuming that the children used, in a consistent fashion, a mental model of the earth other than the spherical earth model. Five alternative mental models of the earth were identified: the rectangular earth, the disc earth, the dual earth, the hollow sphere, and the flattened sphere. It is argued that these models are constrained by certain presuppositions which children form based on interpretations of their everyday experience. Some of these models (the rectangular earth and the disc earth) seem to be initial models children construct before they are exposed to the culturally accepted information that the earth is a sphere. In the process of knowledge acquisition, children appear to modify their initial models to make them more consistent with the culturally accepted model by gradually reinterpreting their presuppositions. Synthetic models (such as the hollow sphere and the flattened sphere) are generated by children as a solution to the problems arising from the inconsistency between their initial model of a flat earth and the culturally accepted, scientific model of a spherical earth. Children come to understand that the earth is a sphere only when the presuppositions that gave rise to their initial models have been reinterpreted.     

Using a local Web browser as a multimedia platform for lecture and presentation support

As an alternative to commercial multimedia systems, lecturers may wish to consider using a Web browser for multimedia classroom presentations. Many Web browsers, including Netscape and Mosaic, can be configured for use in a “local mode” (i.e., without an active connection to the Internet). In this local mode, files, graphics, audio, and video can be accessed directly from the hard disk of the instructor’s computer. By using a laptop computer, an LCD panel, and an overhead projector, an instructor can present a classroom multimedia presentation that can also be published on the Web.     

The effects of interaction with the device described by procedural text on recall,true/false,and task performance

In two experiments, subjects interacted to different extents with relevant devices while reading two complex multistep procedural texts and were then tested with task performance time, true/false, and recall measures. While reading, subjects performed the task (read and do), saw the experimenter perform the task (read and see experimenter do), imagined doing the task (read and imagine), looked at the device while reading (read and see), or only read (read only). Van Dijk and Kintsch’s (1983) text representation theory led to the prediction that exposure to the task device (in the read-and-do, read-and-see, and read-and-see-experimenter-do conditions) would lead to the development of a stronger situation model and therefore faster task performance, whereas the read-only and read-andsee conditions would lead to a better textbase, and therefore better performance on the true/false and recall tasks. Paivio’s (1991) dual coding theory led to the opposite prediction for recall. The results supported the text representation theory with task performance and recall. The read-and-see condition produced consistently good performance on the true/false measure. Amount of text study time contributed to recall performance. These findings support the notion that information available while reading leads to differential development of representations in memory, which, in turn, causes differences in performance on various measures.     

Humor As a Stress Moderator in the Prediction of Blood Pressure Obtained during Five Stressful Tasks

In five consecutive stressful tasks we examined the role of humor as a potential stress moderator using systolic and diastolic blood pressure as an indication of cardiovascular reactivity. In all five tasks, the Coping Humor Scale interacted with sex in the prediction of blood pressure. The same pattern was found in response to each of the five tasks: Females who were higher in coping humor exhibited lower systolic blood pressure than females scoring lower on coping humor, while the reverse characterized males; males who scored high on the coping humor scale exhibited higher systolic blood pressure than males scoring low on that scale. Similar though less robust results were found when the Situational Humor Response Questionnaire was used as the measure of humor. In the Cold Pressor Task, which involves pain and endurance, interactions were found between humor, sex, and trials indicating a stress-moderator effect. The absence of interactions indicating stress moderation in most of the analyses with the other four stress tasks suggests that humor may play more of a role in moderating the impact of uncontrollable and passively experienced stressors. Tasks requiring more active, problem-solving behavior may be less amenable to the beneficial effects of humor. The findings do not clearly resolve the questions about the role of humor in effecting responses to stress. However, they do suggest that the subjects' sex may be an important consideration when evaluating the impact of humor as a stress moderator.     

The role of symmetrical and asymmetrical social conflict in cognitive change

We asked whether dyads consisting of nonconservers of liquid would be more likely than solo controls to change to a conservation answer when each child gave symmetrically conflicting answers from different perspectives ("more" versus "less" from different viewpoints). We also asked whether nonconservers are more likely than conservers to abandon their answers in conserver + nonconserver dyads. In order to stimulate the perspectival conflicts in the nonconserver + nonconserver dyads, the partners experienced artificial displays in which the two possible answers were afforded by different views of the apparatus. We found no evidence that social conflict of the kind engineered in the nonconserver + nonconserver dyads stimulates cognitive change. Our evidence that nonconservers tend to adopt the conservation answer of their partners was less strong than that collected in previous studies, but this may have been due to the fact that, contrary to previous studies, the children's social dominance relations were affecting the outcome. We concluded that the ineffectiveness of symmetrical social conflict is consistent with Piaget's conception of nonconservers as children insensitive to the perspective-relative nature of their judgments.     

Reducing Avoidance of Social Interaction with a Physically Disabled Person by Mentioning the Disability Following a Request for Aid1

The effectiveness of strategies for reducing avoidance of social interaction with a physically disabled person was experimentally investigated. Female college students privately expressed their preference for social interaction before and after learning the other was a female in a wheelchair or nondisabled. The results provide evidence for the effectiveness of mentioning the disability following a request for aid related to the disability (the Request-mention Strategy). Change in preference for social interaction was more positive when the disabled person employed the Request-mention strategy than when she said nothing. Requesting aid without mentioning the disability was not found to be effective. A request for aid unrelated to the disability was clearly ineffective. The disabled person who said nothing was avoided, in comparison to when the same person was nondisabled. Favorability of impressions of the other, as measured by ratings of her characteristics, was not influenced by the experimental conditions.