Preece and Shneiderman  conducted a literature review to identify possible motivations for different levels of participation in online communities. For example, they found that a welcoming environment, safety, privacy, support for newcomers, encouragement by individuals they trusted or respected, contacts to answer their questions, and frequently updated and well-organized content were some factors that motivated readers. The ease of making contributions, recognition of the quality and quantity of their contributions, and gaining visibility or awards for their contributions were some factors that encouraged contributors. Trust and empathy that promoted belonging to the community, altruism, and the desire to build a reputation were some factors that encouraged collaborators.