This paper describes research on the use of journals in a general education chemistry course for elementary education majors. In the journals, students describe their understanding of a topic, the development of that understanding, and how the topic connects to their lives. In the process, they are able to engage in reflection about several things. How the frequency and nature of those reflections relate to overall course outcomes, the content and quality of final exam essays on those topics, and student metacognition in problem solving are the basis of this paper. The following types of reflections were identified in the journals: action, prior knowledge, project ideas, text resources, classroom events, and monitoring of knowledge. A multiple linear regression analysis of the students' final course grade earned versus student grade point average (GPA), composite score on the ACT exam, the number of reflections made for each reflection type, and the total number of reflections made throughout all journals was used to determine the significance of the type of reflections made by students in relationship to their chemistry content understanding. The results indicate that students' prior GPA and their reflections on classroom events and their own knowledge correlate positively and significantly with a final course grade. However, student reflections on text resources have a negative and significant correlation with the final course grade. In addition, students' journal entries and final exam responses were coded for similarities in writing. The results indicate that those students who had strong similarities in writing for both their journal and final exam exhibited significantly stronger content understanding on the final exam essay. Finally, metacognition in problem solving, assessed with the Metacognitive Activities Inventory (MCA‐I) survey of metacognition, was also positively correlated with the types of reflection that correlate with overall course performance. © 2012 Wiley Periodicals, Inc. Sci Ed 96:543–565, 2012