CURRICULUM & TEACHING STUDIES | RESEARCH ARTICLE An online tutor for astronomy: The GEAS self-review library

1 Abstract: We introduce an interactive online resource for use by students and college instructors in introductory astronomy courses. The General Education Astronomy Source (GEAS) online tutor guides students developing mastery of core astronomical concepts and mathematical applications of general astronomy material. It contains over 12,000 questions, with linked hints and solutions. Students who master the material quickly can advance through the topics, while underprepared or hesitant students can focus on questions on a certain topic for as long as needed, with mini- mal repetition. Students receive individual accounts for study and course instructors are provided with overview tracking information, by time and by topic, for entire cohorts of students. Diagnostic tools support self-evaluation and close collaboration between instructor and student, even for distance learners. An initial usage study shows clear trends in performance which increase with study time, and indicates that distance learners using these materials perform as well as or better than a com- parison cohort of on-campus astronomy students. We are actively seeking new col- laborators to use this resource in astronomy courses and other educational venues. Subjects: Astrophysics; Mathematics Education; World Wide Web