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This research investigated students' understanding of electrochemistry following a 7-9week course of instruction. A list of conceptual and propositional knowledge statements was formulated, and this provided the framework for semistructured interviews that were conducted with 32 students in their final year of high school chemistry, following instruction in electrochemistry. Three misconceptions identified in this study and five which have been reported earlier are incorporated into an alternative framework about electric current. The framework is grounded on the notion that a current always involves drifting electrons, even in solution. Another area where students' misconceptions were prevalent was in relation to the sign of the anode and cathode. Students who thought the anode was negatively charged believed cations would move toward it, and those who thought it was positively charged were unable to explain why electrons move away from it. Electrolytic cells also proved troublesome for students. Many students did not associate the positions of the anode and cathode with the polarity of the applied electromotive force (e.m.f.). Other students attempted to reverse features of electrochemical cells and apply the reversals to electrolytic cells. The implications of the research relate to students' interpretation of the language that is used to describe scientific phenomena and the tendency for students to overgeneralize, due to comments made by teachers or statements in textbooks.

The purpose of this research was to investigate students' understanding of electrochemistry following a course of instruction. A list of conceptual and propositional knowledge statements was formulated to identify the knowledge base necessary for students to understand electric circuits and oxidation‐reduction equations. The conceptual and propositional knowledge statements provided the framework for the development of a semistructured interview protocol which was administered to 32 students in their final year of high school chemistry. The interview questions about electric circuits revealed that several students in the sample were confused about the nature of electric current both in metallic conductors and in electrolytes. Students studying both physics and chemistry were more confused about current flow in metallic conductors than students who were only studying chemistry. In the section of the interview which focused on oxidation and reduction, many students experienced problems in identifying oxidation‐reduction equations. Several misconceptions relating to the inappropriate use of definitions of oxidation and reduction were identified. The data illustrate how students attempted to make sense of the concepts of electrochemistry with the knowledge they had already developed or constructed. The implications of the research are that teachers, curriculum developers, and textbook writers, if they are to minimize potential misconceptions, need to be cognizant of the relationship between physics and chemistry teaching, of the need to test for erroneous preconceptions about current before teaching about electrochemical (galvanic) and electrolytic cells, and of the difficulties experienced by students when using more than one model to explain scientific phenomena.

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A considerable amount of research in education has focused on gender differences and school learning. In science education there is concern that girls are not achieving as well as they might (Erickson & Erickson, 1984;Kelly, 1978; Welch, 1985). Kelly analyzed an international science dataset for 14-year old pupils in developed countries and found that boys achieved better than girls. The sex differences were consistently large in physics and small in biology. Similar results were reported by Erickson and Erickson for a sample of pupils in grades four, eight and twelve from schools in British Columbia, Canada. Erickson and Erickson found that males achieved at a higher level in science than females. The items for which the differences were most evident assessed understanding of science knowledge and application of knowledge. The differences were most pronounced in physical sciences, but were also evident in biological sciences. There were no measured differences in performance on items which measured process skills.Welch (1985) reported that 17-year old boys achieved about a third of a standard deviation higher than girls on the 1976-77 National Assessment in science. According to Welch, an analysis of national assessment data in 1981-82, revealed that boys achieved at a higher level than girls on concepts such as experimental design, models, hypotheses and errors of measurement. The latter results were obtained from samples of 13-and 17-year old students.Since learning in classrooms involves internal cognitive processing for learners, it is possible that the differences in achievement may have had their genesis in differential opportunities to engage in academic tasks. When teachers interact with students in question-answer sessions they do so with an expectation that certain students will provide the appropriate answers (Tobin & Gallagher, in press). Recent studies (Becker, 1981;Hall, 1982) revealed that boys are spoken to more frequently and are asked more higher order questions. In addition, Hall's study revealed that primary school teachers tend to praise boys for the quality of work and girls for form and neatness. In project work, teachers more often provided boys with instruction on how to complete the project while they tended to show girls how to do it or do it for them. Sadker and Sadker (1985) described the results of a three-year study of fourth-, sixth-and eighth-grade classrooms in the USA. The study revealed substantial Science Education 71(1): 91-103 (1987) 0