This article explores the effectiveness of intervention discussion sections for a college general chemistry course designed to apply research on student preconceptions, knowledge integration, and student explanation. Two interventions, on bond energy and spontaneity, were tested and intervention student performance was compared with that of a control group that did not use the experimental pedagogy. Results indicate that this instruction, which identifies students' initial conceptions and integrates those ideas into class discussion, leads to enhanced conceptual understanding. The intervention group outperformed the control group on a written course midterm, the thermodynamics portion of a standardized American Chemical Society examination, and an in‐depth interview. In interviews, the intervention group students explained the energetics of bond breaking and formation at a more sophisticated level than did the control students. In contrast, control students were more tenuous in their thinking, tended to contradict themselves more when discussing bond energy, and harbored more misconceptions about spontaneity. © 2002 Wiley Periodicals, Inc. J Res Sci Teach 39: 464–496, 2002

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This study examined similarities and differences in study approaches reported by general chemistry students performing at different achievement levels. The study population consisted of freshmen enrolled in a required year-long general chemistry course at the U.S. Naval Academy. Students in the first and second semesters of the course were surveyed using a modified version of the published Approaches and Study Skills Inventory for Students (ASSIST) referred to as the M-ASSIST (Modified Approaches and Study Skills Inventory). Responses to items associated with using deep or surface approaches to studying were examined for students of three achievement levels (A/B, C, and D/F course grades) using both ANOVA and Structured Means Modeling to look for differences in study approaches between achievement levels. Results show that, with only 12 items, the M-ASSIST can be used to measure differences in reported use of deep and surface approaches by students in different achievement groups; that Structured Means Modeling can uncover significant differences that are not apparent with an ANOVA analysis of the same data; and that A/B and D/F students can be classified as reporting using either using primarily deep (A/B students) or primarily surface (D/F) study approaches. C students reported study approaches characteristic of both the A/B and D/F groups, leading to the interpretation that C students may be in an intermediate and possibly transitional state between the higher- and lower-grade groups. These results suggest a new understanding of C students as those who may not fully implement deep approaches to studying but, in general, demonstrate less reliance on surface approaches than lower-achieving students.

In the studies reported here, we investigate the effects of context on students' molecular-level ideas regarding aqueous solutions. During one-on-one interviews, 19 general chemistry students recruited from a two-year community college and a research university in the United States were asked to describe their molecular-level ideas about various aqueous solutions in the contexts of conductivity and boiling-point (BP) elevation. Results indicate that context is important for determining the molecular-level ideas that students express. Specifically, students were significantly more likely to draw pictures of aqueous NaCl as separated ions in the conductivity context compared with the BP elevation context, for which they more often drew "molecular" NaCl. This phenomenon was particularly striking because the students drew molecular-level NaCl(aq) pictures in the BP elevation context just minutes after completing the identical task in the context of conductivity. Additional data from laboratory assignments and course examinations further indicate that, even if students are able to correctly represent the molecular level in some contexts, their knowledge may remain inert in slightly different contexts. The results emphasise the importance of the context dependence of molecular-level ideas and have implications for designing instruction in which students develop robust, coherent understandings that they can apply appropriately in new contexts.

This study investigated relationships between the thinking processes that 28 undergraduate chemistry students engaged in during guided discovery and their subsequent success at reasoning through a transfer problem during an end-of-semester interview. During a guided-discovery laboratory module, students were prompted to use words, pictures, and symbols to make their mental models of chemical compounds added to water explicit, both prior to the start (initial model) and at the end (refined model) of the module. Based on their responses to these model assignments, we characterized students’ knowledge and thinking processes, including the extent to which individual students engaged in (a) constructing molecular-level models that were consistent with experimental evidence; (b) constructing molecular-level models that progressed toward scientific accuracy; (c) constructing molecular-level models that were scientifically correct; (d) making connections between laboratory observations and the molecular-level behavior of particles; (e) accurate metacognitive monitoring of how their molecular-level models changed; and (f) using evidence to justify model refinements. Analyses revealed three thinking processes that were strongly associated with correct reasoning in the transfer context during an end-of-semester interview: constructing molecular-level models that were consistent with experimental evidence, engaging in accurate metacognitive monitoring, and using evidence to justify model refinements. The extent of student engagement in these three key thinking processes predicted correct reasoning in a new context better than the scientific correctness of a student’s content knowledge prior to instruction. Although we did not explore causal relationships, these results suggest that integrating activities that promote the key thinking processes identified into instruction may improve students’ understanding and success at transfer.