The atomic model plays a central role in the study of chemistry and is usually introduced very early in the curriculum. It is therefore important to study the mental pictures of the atomic model formed by students at an early stage of their studies, since misunderstanding this model may prevent meaningful learning at later stages. In the present study an attempt was made to find out students' views about atoms after they have been exposed to chemistry studies for about half a year. The conclusions of this study can be useful for teachers as an aid for considering what their own students may really be thinking about the atomic model and its applications. Indeed, these conclusions (see also ref 1) formed a basis for the development of a new introductory course in chemistry, and a preliminary evaluation of the implementation of this course will be reported. The StudyThe study consisted of three distinct stages.1) A diagnostic investigation of students' views about structure in chemistry. In the present article students' views about the atom will be discussed. Some of the results of this stage will be reported (1).2) Development and implementation of a program designed to prevent some of the misconceptions identified in the first stage. 3) An evaluation of the new program. Diagnostic Investigation of Students' Views about StructureA questionnaire was administered to eleven lOth-grade classes in different high schools in Israel (about 300 students, average age 15 years). All students had studied chemistry for at least half a year. The question relevant to the atomic model was the following:A metallic wire has the following properties: a. conducts electricity b. brown color c. malleable

A study which was designed to identify students’ concepts of simple electric circuits is reported. A diagnostic questionnaire was administered to a sample of 145 high school students and 21 physics teachers. The questionnaire included mainly qualitative questions which were designed to examine students’ understanding of the functional relationships between the variables in an electric circuit. The main findings obtained from the analysis of the responses are current is the primary concept used by students, whereas potential difference is regarded as a consequence of current flow, and not as its cause. Consequently students often use V=IR incorrectly. A battery is regarded as a source of constant current. The concepts of emf and internal resistance are not well understood. Students have difficulties in analyzing the effect which a change in one component has on the rest of the circuit. This is probably due to the more general difficulty students have in dealing with a simultaneous change of several variables.

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Systems thinking is regarded as a high‐order thinking skill required in scientific, technological, and everyday domains. However, little is known about systems thinking in the context of science education. In the current research, students' understanding of the rock cycle system after a learning program was characterized, and the effect of a concluding knowledge integration activity on their systems thinking was studied. Answers to an open‐ended test were interpreted using a systems thinking continuum, ranging from a completely static view of the system to an understanding of the system's cyclic nature. A meaningful improvement in students' views of the rock cycle toward the higher side of the systems thinking continuum was found after the knowledge integration activity. Students became more aware of the dynamic and cyclic nature of the rock cycle, and their ability to construct sequences of processes representing material transformation in relatively large chunks significantly improved. Success of the knowledge integration activity stresses the importance of postknowledge acquisition activities, which engage students in a dual process of differentiation of their knowledge and reintegration in a systems context. We suggest including such activities in curricula involving systems‐based contents, particularly in earth science, in which systems thinking can bring about environmental literacy. © 2003 Wiley Periodicals, Inc. J Res Sci Teach 40: 545–565, 2003

An investigation of students’ knowledge after a traditional advanced high-school course in electromagnetism shows deficiencies of their knowledge in three major areas: (1) the structure of knowledge—e.g., realizing the importance of central ideas, such as Maxwell’s equations (expressed qualitatively); (2) conceptual understanding—e.g., understanding the relationships between the electric field and its sources; and (3) application of central relationships in problem solving. To remedy these deficiencies we propose an instructional model which integrates problem solving, conceptual understanding and the construction of the knowledge structure. The central activity of the students is a gradual construction of a hierarchical concept map organized around Maxwell’s equations as central ideas of the domain. The students construct the map in five stages: (1) SOLVE—they solve a set of problems that highlight the central ideas in the domain; (2) REFLECT—they reflect on the conceptual basis of their solutions; (3) CONCEPTUALIZE—they perform activities that deal with relevant conceptual difficulties; (4) APPLY—they carry out complex applications; (5) LINK—they link their activities to the evolving concept map. This integrative model (experimental treatment) was compared to an isolated treatment of drill and practice or treatment of conceptual difficulties without linkage to the proposed knowledge structure. The comparison shows that students in the experimental treatment performed better than the other students on measures of recall, conceptual knowledge and problem solving. Students in the experimental treatment were also able to transfer and extract central ideas in a domain different than physics.