Open-ended approach originated in Japan during 1970s. Between 1971 and 1976,
Japanese researchers carried out a series of developmental research projects on
methods of evaluating higher-order-thinking skills in mathematics education using
open-ended problems as a theme (Becker and Shigeru, 1997). This approach started
with having students engaging in open-ended problems which are formulated to have
multiple correct answers “incomplete” or “open-ended”. In terms of teaching method,
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one “open-ended” problem is posed to the students first, then, proceeds by using
many correct answer to the given problem to provide experience in finding something
new during the problem-solving process. Mathematical activities generated by openended
problems are very rich and subtle so as teachers can evaluate student’s higherorder-
thinking skills. In a sense, open-ended problem is a good start for creating the
first study lesson for the purpose of study in lesson study approach.
Constructing a good open-ended problem is not an easy task. Suggestions for
constructing appeared on The Open-ended Approach: A New Proposal for Teaching
Mathematics may help doing that. However, for the new comers those suggestions
are still very difficult.
Japanese teachers have long experiences in developing story problems. Thus, they
can implement the suggestions just mentioned in order to make their own open-ended
problems. However, for Thai teachers they are familiar with introducing new contents
to students through some examples and exercises. It is very difficult for them to
organize many mathematical concepts into a problem situation, which is an important
part of open-ended problems. This kind of problem situation has to be formulated so
that mathematical activity can be naturally generated from it. In what follow, the
project introduces the concept of presenting the problem situation in terms of some 3-
5 short instructions instead of presenting in terms of story.
In this way, it is easy for students to start mathematical activity from the given openended
problems. It is also so suitable for teachers to investigate how their formulated
open-ended problems have been engaged in by the students. This will be helpful for
them to revise their open-ended problems which included in lesson plan. This will be
a good start of lesson study.