Hobby activities can be viewed through the lens of informal, free-choice learning. A wide range of hobbies combine fun and learning-intensive practices, and can contribute to scientific literacy. Hobby learning involves clear goal orientation, persistence and effort, and often results in more richly and strongly connected knowledge; traits highly valued in both in and out-of-school science learning. In this study, I used koi hobbyists as subjects to discover and explore hobbyists' information-seeking strategies under different learning scenarios. I approached koi hobbyists' learning about koi and their koi hobby in both quantitative and qualitative ways. I designed a Stage of Engagement Model to illustrate koi hobbyists' engagement with their hobby, and adapted Falk and Dierking's Contextual Model of Learning to explain how personal, socio-cultural and physical contextual factors affect koi hobbyists' learning. An instrument was developed to assess koi hobbyists' experience with keeping koi, knowledge about the hobby, motivation/goals, interaction with other hobbyists, and the information-seeking strategies they used under different learning scenarios. I administered this questionnaire to koi hobbyist communities in the U.S. Pacific Northwest and online. Based on the quantitative analysis, the results supported my hypotheses that koi hobbyists chose different information-seeking strategies based on personal contextual factors such as previous experience, motivation and learning goals; socio-cultural contextual factors such as interactions with other koi hobbyists; and physical contextual factors such as the nature of the problems they encounter. Koi hobbyists also chose different information-seeking strategies based upon their stage of engagement with their hobby. The long-term potential of this study is to offer insights into how learners construct their knowledge by applying different learning strategies under different personal, socio-cultural and physical circumstances, and to provide a framework for the future study of other kinds of hobbies and hobbyists that will help to promote public scientific literacy. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]