From misconceptions to modified teaching-learning strategies in earth sciences in Portuguese secondary education.
This study, based on a constructivist approach to teaching a difficultpart of the Geology Syllabusfor 16-17
year olds concerned with the Theory of Plate Tectonics attempts to make the teaching process in Earth-sdences
easier, more enjoyable and more productive.
The first step was to investigate misconceptions held by a sample of 270 students after spedalist teaching
concerning the nature and origin of continents, oceans, continental drift, the Earth's magnetic field and plates.
The second step involved the designing of a teaching and learning model. This starts with a recognition
phase, in which students elicit their views and is followed by reflexion and reconstruction phases which analyse,
rethink and reorganize students' knowledge. It ends with a re-evaluation phase.
The third step was to plan and implement suitable cuniculum materials.This design incorporated suggestions
from the history and epistemology of science and took into account many of the precursor hypotheses and
theories which were later subsumed by the all-embradng Theory of Plate Tectonics. Four Units corresponding
to each one of the topics referred to above were constructed. The last two units were implemented with an
"experimental" group of five students during a five-weekperiod of extra specialist teaching.
These studies demonstrate:
(i) A rich vein of ideas, tapped before and after the normal period of teaching, which differ from those
of the sdentific consensus. Some of these ideas reveal similaritieswith historicalsteps in the construction
of Earthsoences ' knowledge and others seem to be imponed from others areas of scence,
(ii) The potential of the teaching model as a framework for the designing of curriculum materials;
(lii) That materials designed in accordance with the proposed model diminished students' learning
(iv) That students' conceptual changes were promoted;
(iv) A list of precise recommendations which might be used in a normal secondary school's sdence