Reliance on volunteer participation for collaborative scientific projects has become extremely popular in the past decade. Cutting across disciplines, locations, and participation practices, hundreds of thousands of people all over the world are now involved in these studies, and are advancing tasks that scientists cannot accomplish alone.

Although existing projects have demonstrated the value of involving volunteers to collect data, few projects have been successful in maintaining volunteer involvement over long periods of time. Therefore, it is important to understand the unique motivations of volunteers and their effect on participation practices, so that effective partnerships between volunteers and scientists can be established. This study provides a first look into the relationship between motivation and culture in the context of ecology-focused collaborative scientific projects around the world. Projects in three distinct cultures - the United States, India, and Costa Rica - were examined by triangulating qualitative and quantitative methods followed by a cross-cultural comparison.

The findings reveal a temporal process of participation that is highly dependent on motivation and culture. Initial participation stems in most cases from self-directed motivations. However, as time progresses, the motivational process becomes more complex and includes both self-directed motivations and collaborative motivations. In addition, motivation is strongly modulated by local cultural norms, expectations, and practices. Collaborative and scientific cultures also have an impact throughout the course of the volunteers' participation.

This research provides theoretical and practical contributions: its findings extend current understanding of theories of motivation by showing the connection between culture and motivation, and demonstrate how cultural effects lie at the core of motivation and participation practices in volunteer-based collaborative scientific projects. These findings will also inform scientists, project leaders, educators, administrators, and designers on ways to entice and maintain long-term volunteer participation in collaborative scientific projects that are situated in different cultures.