Most of difficult part of implementing lesson study in a new classroom culture in that how to get started. Teacher who are new to this approach always insist asking where the first lesson comes from, and how to know that is a study lesson worth for continuing study. To shif from making lesson plan according to the topic ascribed in the curriculum to making lesson plans that will satisfy the long goal as expected in lesson study is not an easy work. It demands changing of teachers' beliefs while challenging them to encounter a new paradigm of teaching mathematics. To solve this problem, using open-ended approach in order to create a rich mathematical activity is the most important part of making the first study lesson.
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, 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 open-ended problems are very rich and subtle so as teachers can evaluate student's higher-order-thinking skills. Constructing a good open-ended problem is not an easy task. 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 open-ended problems. It is also so suitable for teachers to investigate how their formulated open-ended problems have been engaged in by the students.
In the 2002 academic year, the Faculty of Education at Khon Kaen University, in an attempt to improve teacher education program, conducted a project to investigate how student teachers develop their worldview on teaching practice and to investigate how school students in the classrooms using the Open-Approach method of teaching recognize their learning experiences. It is aimed at investigating changes in student teachers' worldview on their professional development when using the Open-Approach method of teaching (Nohda, 2000). The project is also aimed at clarifying how school students recognize their learning experiences.
The result of this project is: 1) Fisrt, For teacher. Most of the student teachers developed positive attitudes towards doing research during teaching practice. They have come to realize that doing classroom research can help them develop a wider perspective on how to view their classrooms. Moreover, they acknowledged that classroom research may help improve teachers' everyday practice. Most importantly, student teachers in the project changed their attitudes towards learning from academic learning to life-long learning. Their paradigm on teaching and learning has been shifted into a new one which is seen a unification of their way of life and their learning. This also influences their educational values on their own contribution to society, the core values demanding for Thai society; 2) Second, Students. There are four question to the student and their responses:
1) "Give the reasons why do you like doing activity in the classrooms?"
Responses to the items:
| No | Items | Responses (%) | |
| Boys | Girls | ||
| 1 | More Active | 55.22 | 51.40 |
| 2 | More Thinking | 58.59 | 63.00 |
| 3 | More Playing | 44.75 | 40.20 |
| 4 | Use Art knowledge | 48.71 | 40.34 |
| 5 | Good atmosphere friendship | 46.63 | 39.60 |
| 6 | Do something originally | 54.60 | 53.40 |
| 7 | Feel like independent time | 43.04 | 42.14 |
| 8 | Feel like be more valuable | 44.30 | 28.79 |
| 9 | Do real practice with given materials | 58.58 | 58.49 |
| 10 | Summarize some ideas by themselves (or by own group) | 41.38 | 44.38 |
| 11 | When think out, feel like "genius" | 34.43 | 33.14 |
| 12 | Feel not be boring | 4.62 | 1.79 |
2) "Give the reasons why you do not like doing activity in the classrooms?"
Responses to the item:
| No | Items | Responses (%) | |
| Boys | Girls | ||
| 1 | Boring | 16.59 | 25.65 |
| 2 | Quite not understand questions or direction clearly | 23.70 | 45.74 |
| 3 | Feel that loudly Classrooms | 56.48 | 48.44 |
| 4 | Do not like working in group | 9.66 | 7.34 |
| 5 | Do not like someone in own group | 13.65 | 13.80 |
| 6 | Quite difficult activity | 13.33 | 15.44 |
| 7 | Do not know "to do for what" | 8.80 | 11.85 |
| 8 | Cannot conclude or connect ideas in activities | 16.06 | 16.12 |
| 9 | Feel that do not learn the same things as friends do in other classes | 14.48 | 9.75 |
| 10 | Do not know what to do to answer "the why how questions" | 15.53 | 17.40 |
| 11 | : Teachers cannot observe all students | 16.16 | 14.70 |
| 12 | Time restricted. | 14.09 | 9.90 |
3) "Explain in what issues you change in positive way?
Responses to the item:
| No | Items | Responses (5) | |
| Boys | Girls | ||
| 1 | More reasonable | 42.84 | 40.33 |
| 2 | More skillful in observation | 34.44 | 30.02 |
| 3 | More cooled-heart | 28.77 | 22.07 |
| 4 | Know how to work cooperatively | 53.34 | 59.72 |
| 5 | Dare to ask question | 40.52 | 43.20 |
| 6 | Dare to argue according to their own thinking | 29.39 | 29.67 |
| 7 | Dare to reject what they do not accept | 20.15 | 15.22 |
| 8 | Better communication with friends | 27.29 | 23.94 |
| 9 | Know how to solve problems in a variety of ways | 40.10 | 39.29 |
| 10 | More connected knowledge networking | 23.31 | 23.86 |
| 11 | More enthusiasm | 33.60 | 35.15 |
| 12 | Better achievement. | 28.56 | 26.79 |
4) "Explain in what issues you change in negative way?"
Responses to the item:
| No | Items | Responses (%) | |
| Boys | Girls | ||
| 1 | Do not use the fullest ability or capacity | 24.15 | 24.45 |
| 2 | Lose confidence because of rejection of group | 16.16 | 12.45 |
| 3 | Friends or teacher dominate ideas | 13.02 | 10.49 |
| 4 | Inert | 9.24 | 11.63 |
| 5 | Being bored with maths than before | 11.90 | 12.38 |
| 6 | Tension and anxiety | 22.68 | 29.02 |
| 7 | Worse achievement | 9.23 | 11.54 |
| 8 | Quite show off | 8.81 | 3.74 |
| 9 | Feel not belong to group | 7.76 | 3.45 |
| 10 | Others (not friendship) | 4.40 | 3.00 |
Table 1 and 2 shows a very high consistency that most of the school students like doing activity in the classrooms using Open-Approach method of teaching. The percentage of 2nd choice in table 1 proved evidence that this kind of classroom activity enhancing the students to think than they used to be.
The responses to the items 3-4 mentioned above shows in what way the school students recognize their learning experiences. Nearly 60 percents of the school students learned how to work cooperatively.
[1] Resume of "Open-ended Approach and Teacher Education" by : Maitree Imprasitha.
