Students enter courses with prior knowledge of the subject area. Unfortunately, these naive notions often are misconceptions (or “folk concepts”) that hinder learning of appropriate concepts in the field.

Four causal models describing the longitudinal relationships between attitudes and achievement have been proposed in the literature. These models feature: (a) cross-effects over time between attitudes and achievement, (b) in¯uence of achievement predominant over time, (c) in¯uence of attitudes predominant over time, or (d) no cross-effects over time between attitudes and achievement. In an examination of the causal relationships over time between attitudes toward science and science achievement for White rural seventh-and eighth-grade students, the cross-effects model was the best ®tting model form for students overall. However, when examined by gender, the no cross-effects model exhibited the most accurate ®t for White rural middle-school girls, whereas a new model called the no attitudes-path model exhibited the best ®t for these boys. ß

We report on a long-term, large-scale study of a one-semester, conceptually based, introductory astronomy course with data from more than 400 students over three semesters at the University of New Mexico. Using traditional and alternative assessment tools developed for the project, we examined the pre- and postcourse results for Fall 1994, Spring 1995, and Fall 1995. We find our results are robust: novice students show large, positive gains on assessments of conceptual understanding and connected understanding of the knowledge structure of astronomy. We find no relationship between course achievement and completion of prior courses in science or math; we do find a small to moderate relationship between students’ science self-image and course achievement. Also, we detect little change over each semester in students’ mildly positive incoming attitudes about astronomy and science.

This article describes two related studies that began to explore the validity of scores from select-and-fill-in (SAFI) concept map assessments as measures of students’ connected understanding of science. Scores from SAFI maps created for this purpose and used with middle school students and undergraduate astronomy students possessed high internal consistency and exhibited large mean increases with increased domain exposure. SAFI scores were strongly related to scores from a standardized multiple-choice (MC) achievement measure for middle school students; work with individual students suggested that they used strategies requiring connected understanding to successfully complete the maps. SAFI scores from undergraduate students exhibited large relationships with scores from direct-instruction MC exams and scores from a relatedness ratings measure, taken together and separately. Results provide initial evidence of the validity of scores from SAFI maps as measures of connected understanding of science in middle school and undergraduate introductory science students.

An innovative, conceptually based instructional model for teaching large undergraduate astronomy courses was designed, implemented, and evaluated in the Fall 1995 semester. This model was based on cognitive and educational theories of knowledge and, we believe, is applicable to other large postsecondary science courses. Major components were: (a) identification of the basic important concepts and their interrelationships that are necessary for connected understanding of astronomy in novice students; (b) use of these concepts and their interrelationships throughout the design, implementation, and evaluation stages of the model; (c) identification of students’ prior knowledge and misconceptions; and (d) implementation of varied instructional strategies targeted toward encouraging conceptual understanding in students (i.e., instructional concept maps, cooperative small group work, homework assignments stressing concept application, and a conceptually based student assessment system). Evaluation included the development and use of three measures of conceptual understanding and one of attitudes toward studying astronomy. Over the semester, students showed very large increases in their understanding as assessed by a conceptually based multiple-choice measure of misconceptions, a select-and-fill-in concept map measure, and a relatedness-ratings measure. Attitudes, which were slightly positive before the course, changed slightly in a less favorable direction.