Chemistry Reference
In-Depth Information
concretely ordered perceptions, which require explanation, generalization, and
abstraction by the students themselves. In short: first the macroscopic level
(substances and their properties under specified conditions), and only then the
submicroscopic level (of particles and their properties) and the symbolic level
(of abstract formulas and reaction symbols).
- Criterion of connection:
The degree of organization for the contents and methods should be as high as
possible in the learning process. Different empirical facts (e.g., analytical,
synthetic and spectroscopic data) should be analyzed amongst themselves and
compared in relation to each other. New terms should always be introduced as
knots in a web of relations - an important aspect that Sumfleth [
26
-
28
] and
others emphasized and used for concept maps and advanced organizers. Note,
however, that for beginners the discovery of experimentally observable relations
between concrete substances and their chemical change should always precede
the definition and connection of abstract terms and formulae (
criterion of
concreteness). But this of course does not exclude a quick jump to the abstract
level of representations for more advanced students. Indeed, the learning process
can and should be accelerated more and more by constructing meaning in an
abstract web of relations.
- Criterion of constructivist development:
Terms and reasoning patterns should always be built methodically, step by step,
and in a guided inquiry-based learning process. A progressive, methodical
structure of terms and arguments is necessary to make their interconnections
understandable. According to Aebli [
29
] the learner has to construe every term in
essence for themselves. Therefore, they need enough time and opportunities.
The teacher's job is to encourage the construction of a convincing systematiza-
tion and explanation of empirical facts by the students themselves and to provide
alternative steps for such a learning process if they should fail and need help.
- Criterion of limitation:
New terms, methods, and thought patterns should be taught with only a few
suitable examples until they are consolidated within this limited cognitive
domain. Afterwards they have to be applied to other examples, to guard against
functional fixedness. Unnecessary information, needless devices, and dispens-
able substances and formulae should be avoided. The limitation to relevant
aspects of a learning situation prevents misdirecting stimuli (“noise”) and
encourages problem-solving processes. This has to be considered especially
when experiments in the laboratory have to be planned: the learner, who is
dealing with new substances, equipment, and complex experimental procedures,
easily lapses into the mistake of thoughtless cooking procedures. It is well
known that students often perform experiments in the science class with only
a rudimentary idea of what they are doing, with virtually no understanding of
the purpose of the experiment or of the reasons for the choice of procedure.
Too often it seems that they are doing little more than following recipes.
Their limited working memory cannot take the wealth of information that has
to be coordinated in such a complex learning situation. Information overload
!
