This study examined two students' problem solving approaches: the similarities and the differences in their problem solving approaches, and the general problem solving strategies (heuristics) the students employed were discussed. The two students represent differences not only in terms of grades earned, but also in terms of participation, motivation, attention to detail, and approaches to answering questions and problem solving. Three separate problems were selected for this study: A stoichiometry problem; a fruit salad problem; and a limiting reactant problem. Each student was asked individually on three separate occasions to contribute to this study. There are more similarities in the students' problem solving strategies than there are differences. Both students were able to correctly solve the stoichiometry and the fruit salad problems, and were unable to correctly solve the limiting reactant problem. They recognized that an algorithm could be used for both chemistry problems(a stoichiometry problem & a limiting reactant problem). Both students were unable to correctly solve the limiting reactant problem and to demonstrate a clear understanding of the Law of Conservation of Mass. Nor did they show an ability to apply it in solving the problem. However, there was a difference in each one's ability to extend what had been learned/practiced/quizzed in class, to a related but different problem situation.

Minute papers are brief papers written at the end of a lecture in response to one or two questions posed by the instructor. The answers are discussed briefly at the beginning of the next lecture. We used minute papers to follow students' understanding and response to lecture demonstrations in an introductory general chemistry course. An analysis of these minute papers suggest that the following characteristics are important, when using demonstrations as teaching aids. 1) The purpose of a demonstration should be stated as explicitly as possible. 2) Instructors should be explicit about what is happening and what students should be looking for. 3) Demonstrations should be kept as simple as possible, perhaps illustrating one concept. Finally, we note that students believe that the visual component of demonstrations enhances their comprehension of chemistry concepts.

Based on the Vygotskian perspective that a learner's thinking is constituted in his or her talk and the assumption that student talk in the classroom may occur in more than one way, this study examined discursive practices of students in Korean high school science classrooms. Data came from $11^{th}$ grade earth science classrooms where the Group Investigation (GI) method was implemented. Data source included verbatim transcripts developed from video recordings of class sessions in which students presented their science projects to the whole class and exchanged questions and answers during the presentations. The analysis of the videotape transcripts revealed five different modes of student talk, including 1) retrieving information, 2) reformulating information, 3) building on one's own experience, 4) elaborating current understanding, and 5) negotiating meanings with others. Considering that each of the five modes had different value for learning science, it was recommended that the teacher should engage students in more active modes of discourse and guide them into more sophisticated understanding of science.

Assessing students' knowledge can be a challenging endeavor, as researchers attempt to capture the full complexity and potential development of children's ideas. In this study, the Dynamic Science Assessment (DSA) method (Magnusson, Templin, and Boyle, 1997) was employed to investigate 9-12 year old students' understandings of light, while engaging in multiple tasks with a flashlight with various reflectors and mirrors. The results showed that DSA was effective in providing an opportunity to establish a Zone of Proximal Development, in addition to diagnosing a student's prior understanding. Throughout the interview, a student showed a conceptual model of light as being a solid single entity whose shape can be determined by the shape of the casing of a flashlight. However, as DSA provided phenomena that could not be explained by his unitary model, the student began to re-examine his original conceptual model, and attempted to revise it. This study addressed how Dynamic Science Assessment can help us better understand, not only students' current state of understanding, but also a potential development of understanding in their ZPD. In that sense, this study argues that we should pay more attention to the instructive role of classroom assessment that can promote and support further development of students' deeper understandings.

This review is aimed at the understanding of learning in field-trips relating to education in outdoor activities. The review specifically concerns what studies have been undertaken by seeking evidence from research published between 1950 and 2004. The review indicates three common arguments on learning during field-trips. First, the learning in an informal learning environment based on first-hand experiences is most significant when it has meaning for the learner from field-trips. Second, learning aims and strategies in field-trips have evolved along with world-wide concerns towards the environment. Third, the experiences from field-trips can impact significantly on students' cognitive and affective learning. However, the research of field-trip experiences from outdoor activities has focused on learning outcomes far more than on the learning characteristics which facilitate students' learning. Therefore, further study is required, which can provide clear evidence on how such learning characteristics through field-trips can help studentsto successfully attain educational goals.