For an ethnomathematical
questioning
on the teaching of proof
by
Nicolas Balacheff
Laboratoire Leibniz
CNRS
Grenoble
When one browses the International Handbook for
Mathematics Education, one discovers that the chapter
dedicated to Proof is inserted in between the chapters on
epistemology and on ethnomathematics. Should one see there
simply a coincidence, an evidence of chance in the academic
organization of the book? Maybe not if one considers the
introduction by Ken Clements who tries to give some
coherence to the part of the book that assembles these three
chapters. Whatever the case be, I propose that we engage in
a reflection on this proximity: To begin, in this note I
will affirm that an ethnomathematical questioning is as
necessary for research on the teaching and the learning of
proof in mathematics as is the epistemological questioning
that is more familiar to us (and that actually is a classic
point of departure in this domain of research).
To situate the ethnomathematical
perspective, I take the characterization proposed by one of
its founders, Ubiratán D'Ambrosio: to study the
mathematical practices of culturally identifiable groups in
contrast with academic or scholarly mathematics (but I will
leave the discussion open with respect to the choice to use
the term mathematics to design the practices at stake). One
can also consider the following characterization -- probably
less committed to an epistemological project -- suggested by
Paulus Gerdes, the author of the chapter cited above: to
study the mathematics (or the mathematical ideas) in their
relations to that which constitutes globally social life and
culture (ibid. p. 916). It is remarkable that in his
chapter, where he lists numerous works on ethnomathematics,
Gerdes does not mention a single one that would have
mathematical proof as its focus, whereas there are many
mentions to works on geometric drawings, number, or
computation. Yet, it is difficult to think of a kind of
teaching committed to the initiation on a mathematical
rationality that would not take into account the rationality
external to the class. This statement seems to go without
saying if one judges it on the basis of the ongoing
discussion on the relations between proof and argumentation,
but my intention is to go a farther than that:
I suggest that, in fact,
any didactic transposition of proof in
mathematics takes into account the rationality that is
dominant in the society and the culture within which this
transposition unfolds. The object of teaching
constituted by proof is marked not only by an
epistemological conception carried (and protected) by the
scientific community, but also by a cultural conception of
the relationship to truth and to refutationóa
conception that is proper to the society and the culture
where the didactic system works. An indication that this
conjecture is tenable, also showing its force, is the great
diversity in the vocabulary used by diverse languages and in
different circumstances to speak about proof, about what is
true or valid, and about refutation. This vocabulary can
change along the course of the school years, or between the
official programmes and their effective teaching (we will
see about that in the following months by way of examples
that come from Hungary and Japan). These variations, to
which a mathematician is usually insensible, can entail
serious difficulties in international mathematics education
exchanges which imply translations (a classical example is
that of the distinction between preuve and d monstration,
that romance languages permit to make and that is barely
tolerated in English ). But this is not just a matter of
words, it has important theoretical implications! These
difficulties cannot be overcome without an ethnomathematical
questioning enabling us to understand the origin of this
diversity and what does this diversity mean with respect to
the relationship between school mathematics and its social
and cultural context. In a book on cognitive development
which takes into account social context, Barbara Rogoff
notes, apropos of a field observation, that what separates
the observed from the observer is not so much each
oneís ìlogicî as the possibility to
reach an agreement on what could be accepted as true (ibid.
p. 30). What is at stake is the recognition and the taking
into account of the ìinstitutionalî character
of the decision and control rules that are related to the
use of representations, computational techniques, and all
the things that Alan Bishop calls symbolic technologies of
mathematics. How does school take into account these rules
and the ìformalizedî (but usually implicit)
practices that accompany their usage?
I solicit those who are interested by these questions to
contribute to initiate this ethnomathematical questioning by
responding some questions that I formulate below or by
soliciting the contribution of others who may not have
access to the web but could provide some information:
- What are the words that are used in your language
(and within your culture) to translate d monstration and
preuve? What aspects are distinguished by the various
possibilities? What terms are used in teaching (according
to the levels of schooling)?
- What are the words used in your language (and within
your culture) to translate contre-exemple and r futation?
What aspects are distinguished by the various
possibilities? What terms are used in teaching (according
to the levels of schooling)?
- In your culture or society, how does one express the
fact that one is certain on the validity of a statement
or that one is confident on its truth? Are there
different linguistic or pragmatic ways? What happens in
school?
- How does one express a disagreement in your culture
or in your society? Are there different linguistic or
pragmatic ways? What happens in school?
Bishop A. J. et al. (eds.) (1996) International
Handbook of Mathematical Education (esp. Ch. 22, 23
& 24). Dordrecht: Kluwer Academic Publishers.
Bishop A. J. (1988) Mathematical Enculturation.
Dordrecht: Kluwer Ac. Pub.
d'Ambrosio U. (1993) Etnomatemática.
São Paulo: Editora Atica S. A.
Gerdes P. (1996) Ethnomatematics and Mathematics. In: Bishop
A. J. et al.(eds.) International Handbook of Mathematical
Education (pp.909-943). Dordrecht: Kluwer Academic
Publishers.
Rogoff B. (1990) Apprenticeship in thinking. Oxford
University Press.
NT. A way to maintain some of
the distinction in English is to translate preuve as proof
and d monstration as mathematical proof.
Reactions?
Remarks?
The reactions to the contribution of Nicolas Balacheff
will be
published in the November/December 99 Proof Newsletter
©
N. Balacheff
Free
translation from French, Patricio Herbst
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