Duarte Costa Pereira

Reaction and spontaneity: the influence of meaning from everyday language on fourth year undergraduates’ interpretations of some simple chemical phenomena

Fourteen fourth‐year undergraduate chemistry students were interviewed in the context of some simple chemical phenomena to find out their concepts of ‘reaction’ and ‘spontaneous’. The students were asked to discuss and to decide in four situations whether or not a chemical reaction had taken place and then, if one had, to decide whether or not the reaction was spontaneous. The differences between the chemical and everyday meanings of the words reaction and spontaneous are discussed and the differences are used to interpret the students’ ideas. The students tended to take decisions about ‘reaction’ using criteria which were based on superficial, mostly visual criteria. If they could not ‘see’ a new substance being formed they tended not to refer to the change as a reaction. The role of the solvent in a reaction in solution was not considered. The interpretation of ‘spontaneous’ was very close to the everyday meaning of the word, relying on the idea of external interference rather than thermodynamic criteri...

Teachers’ language and pupils’ ideas in science lessons:can teachers avoid reinforcing wrong ideas?

The lessons given by seven secondary school science teachers on the subject of ‘heat’, temperature and energy were observed and all of the teachers substantive statements were recorded. The language used was descriptively analysed and categorized in order to find out the nature of the inherent ideas. It was found that the common misconceptions found in studies of pupils’ work in this topic area (such as the caloric notion of heat having substantial properties similar to a fluid) were embedded in the linguistic metaphors and analogies used by the teachers when discussing with the pupils. The misconceptions are thus not simply brought into classrooms from everyday discourse and experience: they are present in the classroom itself in the language of teaching. It is argued that the common misconceptions stand little chance of being eradicated in this situation, since they are continuously being unintentionally reinforced by the teacher. Teachers, who understand the ideas, cannot easily pass on their knowledg...

Hypermedia and ITS

ITS research is likely to represent the most important means for optimizing the interface ergonomy of hypermedia, particularly in learning situations and regarding mainly three points. First, the cognitive model of the user, which is related to the activity of exploring hypermedia documents. Second, the analysis of the preferences and search strategies of each user as well as the nature and level of the information processed, will lead to hypermedia in which the user diagnostic module must itself be intelligent or, in other words, be capable of learning. Finally, the system should be able to determine preferential paths for learning in order to direct the student-users.

Psychopedagogic aspects of hypermedia courseware

One of the most promising technological advances for education is represented by the text and image driven, non-linear techniques of information handling and searching of the hypermedia architectures.We will not be arguing in favor of the important role these techniques will play in CAL [1], because we think everybody agrees on that point. It also seems inappropriate to theoretically explain, using currently accepted learning theories, the reasons for the purported efficiency. Instead, based on an example that we are developing, we will suggest some research lines that will help to improve the pedagogical uses of hypertext. Nevertheless many questions arise about the efficient use of these techniques. The answers to these questions are vital, but we are not able to tackle all of them. We shall attempt to answer the following: What are the hypermedia characteristics that deserve to be studied in order to improve the efficiency of courseware? Theoretically there are three types of hypermedia: non-structared, semantically structured, and hierarchically structured. In the case of educational programs, all these types occur together in every program, except perhaps non-structured hypermedia environments, which we very much doubt exists.

Potential role of age, sex, body mass index and pain to identify patients with knee osteoarthritis

To evaluate the potential role of age, sex, body mass index (BMI), radiographic features and pain in knee osteoarthritis (OA) case ascertainment.

Hypermedia and Science Education — The Case of Chemistry

Hypertext is recommended in the educational literature for support of subject matters where different opinions and interpretations may exist (Costa Pereira et al., 1990d). Apparently the robustness of the science paradigm excludes the scientific subjects from this type of support. This is anyway only apparent because the existence of an overwhelming paradigm doesn’t mean that the scientific discourse is unified. Apart from the universal pedagogic existence of the division theme/rheme (Gomes & Costa Pereira, 1991), theme referring to the topic itself and rheme to its explanation, it is important to understand that science has not even a unified thematic discourse but, on the contrary, has different discourses where not only the referents, but also the rules change dramatically. This comes not only from the occasional use of models (analogical and sometimes even pictorial representations (Costa Pereira, 1989 and 1990c)), from the use of specific sign systems (as the symbols and equations in chemistry (Gomes et al., 1989)) but also, and above all, because the epistemologic foundations of most established sciences are, in fact, hybrid. For instance, physics (Harre, 1984) adopts in part the Aristotelian views of substance and also the more modern view of action at a distance and the notion of field which are difficult to make compatible. On the other hand, since the eighteenth century all sciences have evolved, thanks to their reductionism and mechanicism, but nowadays, with the advent of chaos theory (Gleick, 1989) through non-linearity, it is necessary to live also with these ideas. This has important consequences, as for instance, the geometry implied by the latter is very different from the conventional euclidean geometry as it is based on the notions of self-similarity and recursion (fractal geometry).

Designing Hypermedia for Computer Assisted Career Guidance

Computer career guidance (CACG) systems have become one of the most commom comprehensive guidance resources, both in educational and employment settings (Association of Computer Based Systems for Career Information, 1990; Chapman & Katz, 1982; Sampson, Shahnarasian, & Reardon, 1987, 1988). The first systems were developed in U.S.A. and in Canada, in the mid 1960s, but from the early 1970s, a number of systems have been developed in Europe, too, with inspiration from North America (Plant, 1989; Taveira & Campos, 1989; Watts & Ballantine, 1981).

Towards a Hypertext Semiotics

Before considering Hypertext as a semiotic object we need to consider some rational previous aspects. First, we would like this brief contribution to be considered as a starting point for someone who has just arrived on the Hypertext Planet and not at all as the end point of the research already developed in this domain. Second, we would like to take it as a provocation: this is because on a former occasion (Gomes et al., 1989; Gomes & Costa Pereira, 1990), we rejected the term Hypertext, and proposed another, Holotext, for reasons explained then. It is usual to forgive newcomers a certain boldness even if it is too much as in this case.