Recent advances in interactive web technologies, combined with widespread broadband and mobile device adoption, have made online collective action commonplace. Millions of individuals work together to aggregate, annotate, and share digital text, audio, images, and video. Given the prevalence and importance of online collective action systems, researchers have increasingly devoted attention to questions about how individuals interact with and participate them. I investigate these questions with the understanding that an individual's behaviors and attitudes depend in part on what they know and believe about how the online collaborative system operates--the "nuts and bolts," so to speak. In this dissertation I examine how "social operational information"--information and beliefs about the other people who act in online collective action systems--can influence individuals' attitudes, assumptions, behaviors, and motivations with respect to those systems. I examine the role of social operational information from two distinct but related perspectives. First, I employed a social psychological laboratory study to examine the influence of a specific type of social operational information: "relative competence feedback". Experimental findings demonstrate that individuals who received information that they were of low relative competence compared to others contributed less to a collective good compared to those who received either average or high relative competence feedback. Two key attitudes about abilities and responsibilities in inter-dependent situations--"self-efficacy" and "social responsibility"--mediated the competence-contribution relationship. Furthermore, individual participants' stable preferences about the distribution of rewards for themselves and other people (social value orientation) moderated the observed changes in contribution rates across experimental conditions. Secondly, I conducted a qualitative interview study of Wikipedia's infrequent editors and readers. The study focused on documenting and understanding participants' attitudes, beliefs, and assumptions about Wikipedia's social system and the other individuals who contribute to it. Interviews focused on questions about the nature of Wikipedia and its' user-generated system, the characteristics of the people who write Wikipedia, and the motivations that encourage their participation. Qualitative analysis revealed a variety of tensions around the nature of Wikipedia as an open, user-generated system, as well as between widespread negative stereotypes of contributors as geeks, nerds, and hackers and equally prevalent positive assumptions about their pro-social motivations for contributing to Wikipedia. I argue that these tensions reveal a transition towards a view of online collaborative work as open, creative, and focused on collaboration, dominated by intrinsic motivations such as passion, interest, and a desire to contribute something to the world. This emerging view of work on Wikipedia is captured by Himanen's notion of "The Hacker Ethic". Finally, I explore how qualitative and experimental findings can speak to each other, and discuss some methodological challenges and best practices for combining experimental and qualitative methods. I argue that triangulating qualitative and experimental results in the context of this study facilitates: (1) lending detail and nuance to our understanding of complex attitudes such as social responsibility, and (2) improving the ecological validity of experimental findings by vetting assumptions about competence and social roles/responsibilities in a real-world context. [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.]