Toulmin’s (1958) model of argument was employed in the analysis of verbal protocols obtained during the solving of ill-structured problems. The participants were experts in the domain under study. For the analysis the Toulmin model was extended in order to enable description of lines of argument found in protocols as long as 10 paragraphs. Results included: (1) That while the protocol was comprised of a large number of specific arguments, the analysis provided for tracing a solver’s line of argument. (2) (...) On occasion datum and backing were difficult to distinguish. (3) Warrants essentially were not stated, although substantial backing was provided. However, as perhaps would be expected, the Toulmin model did not provide for delineation of components of the problem-solving process. A second analysis assuming a “higher level” problem-solving structure and a “lower level” argument structure produced an integrated problem-solving – argumentation structure depicting how reasoning is used in relation to particular task goals. Finally, at a more general level, problem solving was considered as a classical rhetorical structure. (shrink)

Central African highland farmers' perceptions of common bean disease were investigated using both phytopathology and anthropological techniques. Farmers rarely mentioned diseases as production constraints in formal questionnaires. More participatory research showed farmers often related disease symptoms to the effects of rain and soil depletion for fungal diseases, or to varietal traits for bean common mosaic virus. Rain or moisture is divided into numerous forms through which it can damage plants, both physically and through putrefaction. Most conditions associated with putrefaction appear (...) to be linked to pathogens. Farmers have an understanding of plant health closely related to their concept of human health. In plants, this understanding is based on the prior state of plant health. Conceptually, local disease management strategies are based on prevention by managing the conditions that promote good plant health rather than by treating disease symptoms. Intervention strategies that build on local knowledge are encouraged. (shrink)

This paper is concerned with the processing of informal arguments, that is, arguments involving “probable truth.” A model of informal argument processing is presented that is based upon Hample's (1977) expansion of Toulmin's (1958) model of argument structure. The model postulates that a claim activates an attitude, the two components forming a complex that in turn activates reasons. Furthermore, the model holds occurrence of the reason, or possibly the claim and the reason, activates values. Three experiments are described that provide (...) support for the model. (shrink)

Habitat dioramas depicting ecological relations between organisms and their natural environments have become the preferred mode of museum display in most natural history museums in North America and Europe. Dioramas emerged in the late nineteenth century as an alternative mode of museum installation from taxonomically arranged cases. We suggest that this change was closely connected to the emergence of a biogeographical framework rooted in evolutionary theory and positing the existence of distinct biogeographical zones. We tie the history of dioramas to (...) earlier visual resources such as the thematic images that Wallace introduced to illustrate his 1876 Geographical Distribution of Animals. These images were unique in their time because each of them simultaneously depicted animals from several different taxa, rather than only one, as well as the ecological relations between animals and their habitats. Both, visually and with respect to their function within biogeography, these images presaged the habitat dioramas that came shortly afterwards. Not coincidentally, Wallace explicitly advocated the use of dioramas for museum display in ongoing debates on museum reform. Wallace 's suggestions were put into practice by committed evolutionists such as Gottlieb von Koch who pioneered the diorama installation in the Grand Ducal Museum in Darmstadt in 1906. As in Wallace 's illustrations, Koch's dioramas were designed to respresent biogeographical zones. This paper explores the function of these visual displays of biogeographical relations. It argues that, in both the scientific and public realms, biogeogaphical zones were defined and constructed by visual means; recourse to visual representation was more than a method of communication. (shrink)