Sekiguchi Y. (2000)
Mathematical Proof, Argumentation, and Classroom Communication: A Japanese Perspective.

Contribution to: Paolo Boero, G. Harel, C. Maher, M. Miyazaki (organisers) Proof and Proving in Mathematics Education. ICME9 TSG 12. Tokyo/Makuhari, Japan.

© Yasuhiro Sekiguchi

This proposal discusses relationships between argumentation and mathematical proof from the cultural perspective. Recently, some researchers suggest that learning of mathematical proof or proving should be located in the context of argumentative activity, that is, in the exchanges of conjectures, explanations, justifications, and refutations among students. I discuss this idea from a cultural perspective, using Japanese culture as a case, and indicate that careful consideration on cultures of the society and classroom is necessary to actualize the learning of mathematical proof in argumentative activities.
  For this purpose I use the concept of communication as an overall framework. This is because I consider that (1) cultural aspects are well-reflected in the style of communication, (2) argumentation is a type of verbal communication, and (3) mathematical proof is an important component of communication in the mathematical community.
  In the following, I first describe communication styles in Japanese culture, comparing with those of the Western culture. Then, I discuss argumentation and mathematical proof in Japanese schools, focusing on how they are related to general styles of communication in Japanese culture.

Communication and Argumentation in Japanese Culture

Barnlund (1975) pointed out that Japanese traditional culture does not always place the highest value on verbal communication in the communicative activity. The goal of communication in public is a harmony ("wa") among the participants. Difference between opinions among the participants is conceived of as a threat to the harmony. Therefore, people tend to avoid explicit expression of disagreement in public. The harmony is often symbolized by uniformity or homogeneity in appearance, behaviors, expressions, and so on, within a community. The community emphasizes following social obligations ("gimu," "giri," "tatemae") of the community. Cooperation rather than competition is highly valued within a community. Therefore, a person who disregards the community's obligations sometimes receives rather emotional reactions--e. g., accusation, isolation, or expulsion--than rational ones. It is well-known that even in academic conferences, Japanese do not openly argue with each other very much. Expressing direct opposition is considered impolite: Opposition is usually indirectly or euphemistically expressed. This communication style of Japanese may be called the "group" model (Moeran, 1984).
  Individuals do not always agree with each other, of course, in any culture. They need to have opportunities to express their own opinions and negotiate them. The group model does not describe those opportunities. As Moeran points out, there is a complementary model--a "social exchange" model--of Japanese communication, where individuals exchange their spontaneous opinions and feelings (Moeran, 1984). In informal opportunities like private talk with close friends or conversation in a drinking party of coworkers, people express rather openly their natural opinions and feelings ("ninjo," "honne"), and negotiate them.
  For the process of exchanging opinions in the Western cultures, Toulmin (1958) described a pattern of argument ("Toulmin model"), consisting of four components: claims, grounds, warrants, and backing. These are "armaments" of the Western style argumentation. As Lakoff and Johnson (1980) suggest, a "war" metaphor underlies this argumentation:

"Many of the things we do in arguing are partially structured by the concept of war. Though there is no physical battle, there is a verbal battle, and the structure of argument--attack, defense, counterattack, etc.--reflects this." (Lakoff & Johnson, 1980, p. 4)

In contrast, in Japan, exchanging talks in either public or private is usually referred to as "hanashi-ai": The word means mutual conversation or consultation, and does not signify a war. Because people try to avoid direct confrontation, they try to put their opinions ambiguously so that they can withdraw or change them easily when others indicate opposition. As a result, people in "hanashi-ai" do not usually bring up such full logical defense devices like "grounds," "warrants," and "backing." Even in those situations where the social exchange model is working, people tend to avoid bringing up logical armaments because they feel that arguing logically is impersonal ("katakurushii"). In ordinary life, logic ("ronri") is often equated with "rikutsu." The latter is often used derogatorily. Arguments that emphasize "rikutsu" are considered superficial and not reaching the audience's hearts. Therefore, even in the social exchange model, logical argumentation is not preferred.

Argumentation and Proof in Japanese Classrooms

In Japanese schools, the classroom processes contain both formal and informal opportunities, in the sense of the general Japanese culture. Classroom lessons usually contain processes of exchanging opinions in a whole-class or small-groups. These processes are again called "hanashi-ai" as in the adult societies, and teachers play an important role for managing "hanashi-ai" in the class.
  As mentioned already, confronting someone's argument in public is not encouraged in Japanese culture. In school, children are not totally socialized to the adult culture, however. They sometimes directly express opposition or disagreement in classroom talks, and may endanger the classroom harmony. The classroom teacher plays an important role here. The teacher expresses respects to individual children's ideas, whether they are valid or not. The teacher tries to use a conflict between children's claims as a good opportunity to deepen children's understanding of the issue in question. That is, the teacher handles the conflict not just as a problem between the involved children but instead frames a problem of the whole class from it: The conflict is shared among the classroom participants, and becomes "our" problem (cf. Lewis, 1995, pp. 125-130). The teacher encourages the whole class to think about it and give suggestions. All the class members are supposed to work together towards resolution of the problem, so that the reached resolution produces a recovery of the harmony in the classroom community.
  Japanese teachers pose a rather challenging problem in the opening of lesson. They encourage children to present their own ideas for solving the problem. In the lesson, the teacher asks children to do "hanashi-ai" in small groups, or a whole class. Because the problem is difficult, children often make wrong conjectures and ideas, and procedural mistakes. Also, since the problem is often open-ended, children may produce several different solutions. The teacher encourages them to compare their ideas and solutions with each other. At those occasions, counterexamples may be found, and counterarguments may occur. The teacher intentionally uses such opportunities to stimulate children's thinking. Japanese traditional discipline (or moral) places great emphasis on reflecting ("hansei") on one's own mistakes and appreciating contributions from others, so that it encourages cooperation among children (cf. Lewis, 1995). Though "hanashi-ai" may eventually conclude which solution is better, correct, efficient, elegant, or whatever, competition among children is generally discouraged. Therefore, in principle, no winner and no loser exist in "hanashi-ai," unlike the Western-style argumentation.
  Mathematics lessons in Japanese schools emphasize "wakaru" (understanding) of mathematical ideas. Memorizing formulas and mastering skills are not considered the central theme of learning. In school mathematics, we emphasize the importance of asking questions "why?" in thinking: "Why" questions encourage asking to search the "origin" (causes or basic premises) of the phenomenon in focus and to describe a (causal or logical) path ("sujimichi") leading from the origin to the phenomenon. Answer to the "why?" is termed "wake" or "riyu" (reasons). The activities of finding and explaining "wake" or "riyu" are considered essential for learning of mathematical proof in Japan.
  Mathematical proof is called "shoumei" in Japanese. In junior high school, explaining "wake" or "riyu" is often simply called "setsumei." Activities of doing "setsumei" are commonly held before introducing the concept of mathematical proof "shoumei." The terms "wake," "riyu," and "setsumei" are all commonly used in students' everyday life. In contrast, the term "shoumei" rarely appears in everyday life; therefore, it has to be explicitly introduced and instructed in school. In Japanese schools, the term "shoumei" is first introduced to the students in geometry lessons of the eighth grade mathematics. In lesson, "shoumei" of a mathematical claim is usually defined either as an act of showing logically that the claim is true, or as a written document of that act. And, "shoumei" is conceived of as a special kind of "setsumei," characteristic of mathematics.
  The instruction of mathematical proof has been traditionally conceived of in the above mentioned group model of Japanese communication. "Shoumei" has to deduce the stated claim by following the accepted premises. This corresponds well to the idea of "following the social obligations of the community." Therefore, the group model of Japanese public communication seems to fit well the process of showing proofs. The instruction of mathematical proof and the structure of "hanashi-ai" in Japanese classrooms seem more consistent with Japanese traditional communication styles than Toulmin model.

The above conclusion suggests that it would be culturally difficult for Japanese to fully actualize the argumentation of Toulmin model in the classroom, and to teach mathematical proving as argumentative activity. The idea that learning of mathematical proof should be located in the context of argumentative activity seems highly influenced from the Western cultures. Should Japanese educators adopt that idea?

References

Barnlund D. C. (1975) Public and private self in Japan and the United States: Communicative styles of two cultures. Tokyo: The Simul Press.
Lakoff G., Johnson M. (1980) Metaphors we live by. Chicago: The University of Chicago Press.
Lewis C. C. (1995) Educating hearts and minds: Reflections on Japanese preschool and elementary education. Cambridge, UK: Cambridge University Press.
Moeran B. (1984). Individual, group and seishin: Japan's internal cultural debate. Man 19, 252-266.
Toulmin E. S. (1958) The uses of argument. Cambridge. UK: Cambridge University Press.