In citizen science, project leaders rely on volunteer contributors to collect, classify, and analyze data in both natural and digital environments. To be successful, volunteers are often provided with specialized training that supports the learning goals of the project. Yet, little is understood regarding the contextual influences of both the project "and" the volunteer that affect what those learning goals are and how they are supported. Additionally, the use of technology to deliver and support learning opportunities to volunteers is increasingly relied upon regardless of the project's physical setting. However, the degree to which the transition to digital supports for volunteer learning has been successfully leveraged by projects to meet their unique goals and the needs of their volunteers has not been thoroughly examined. Unlike much of the research that is available, this exploratory study examined volunteer learning from a different perspective, that of the citizen science project leader, and investigated the influences at play that impact the project's volunteer learning goals and the project's ability to support those objectives. Through semi-structured interviews with project leadership and the analyses of digital and physical documents, this study revealed the need for a new framework to better understand how the personal, social, organizational, and physical contexts of the project and their volunteers impact a citizen science project's approach to volunteer learning. This dissertation introduces the Contextual Model of Citizen Science Learning to meet this need. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]