The purpose of this study is to find out which type of small group has the best effect on the science conceptual learning about photosynthesis. The small groups can be divided into four types: The heterogeneous group and three kinds of homogeneous groups, which have different student ability level - low, middle, and high. According to the literature review, each small group has three members.
We analyzed the change in photosynthetic concepts through the lecture classes adopting the ecological niche approach. The process visually revealed the cognitive change in the science conceptual learning.
This survey was performed to 1,107 7th graders who live in various types of habitats, ranging from big cities to small towns. According to the previous study, the photosynthesis units can be divided into four categories: the photosynthesizing place, the substances of photosynthesis, required materials for the photosynthesizing, and environmental factors affecting photosynthesis. The questionnaire used in this survey covers all the four categories mentioned above and the concepts corresponding to each category. The subjects were required to determine the degree of relevance between the category and the concepts, marking 1 to 30 scores. (The stronger the relevance, the higher the scores.) They were also called on to describe the definition of each concept. Each of their description was scored on a scale of 1-5. (The more correct the description, the higher the scores.)
The result can be summarized as follows: The overlapping status in the concept graph showed that all four types of small groups - The heterogeneous group, the high-level, middle-level, and low-level homogeneous groups - had improved students'' conceptual understanding. This is because small group activities, regardless of the type of small groups, are cooperative so that students can learn from their group members.
According to the status in the overlapping conceptual graph, the heterogeneous small group occupied the highest status in the conceptual understanding, followed by the high-level homogeneous small group. The middle-level homogeneous small group took the third, and the low-level homogeneous small group occupied the lowest status. This is because students in the low-level homogeneous group are less likely to learn from peers since all the group members have very limited knowledge.
Therefore, it is highly recommended to adopt the heterogeneous small group in order to make the most of the peer-learning effect.