The purpose of this study was to investigate the process of constructing pre-service teachers` scientific knowledge information through collective intelligence. We selected the` Appropriate Technology` (A.T.) as the subject for formation of scientific knowledge. Twenty nine pre-service teachers of the course `Scientific Thinking and Writing in Science Education` were allowed to freely post information whenever they wanted. They presented their full opinions, interacted with each other, and assessed the other` information on the website for a month. The way of posting was as follows. After one pre-service teacher had written the information about A.T. on the website, the other assessed the text and added or modified the writing. This process continued. We analyzed every writing they posted and questionnaire which contained the reason why they modified the text. The result was as follows. Pre-service teachers formed collective intelligence through four stages. First, pre-service teachers started to find the information related to the subject and they just added the information behind the other`s writing. In the second stage, information was added, too. But me difference was that the information they selected carried values for having certain views. Third, they organized their writings with logical and critical thinking. Finally, they revised their overall writing. The results showed that students could develop their critical thinking and they could learn the way of communication from the process of collective intelligence. We found the forming process of knowledge by collective intelligence, and explored the various involving patterns and thinking activities in the process. Based on this research, we expect the improvement of students` logical and critical thinking through the various classes using collective intelligence.