Background/Question/Methods PROJECT BUDBURST (www.budburst.org) is a national citizen science initiative designed to engage the public in observations of phenological (plant life cycle) events that raise awareness of climate change, and create a cadre of informed citizen scientists. PROJECT BUDBURST also is an important way of developing a unique national dataset for examining biological responses to climate change. Like many other citizen science programs there is a great potential to combine broad educational goals with scientific research.  The key question we are asking here is what are the general principles required to guide the design of such a project so that credible and consistent data can be acquired and so that data can be easily integrated into ongoing research on plant phenology.  We developed a series of protocols for data acquisition including a web-based data model, and extensive non-technical background materials to increase accuracy of contributed data. We discuss both the general conceptual and specific technical issues raised by this program and how they may help inform similar citizen science efforts in ecology.

Results/Conclusions Project budburst was successful in engaging thousands of people and documenting over 900 phenological events across the country during its first trial year in 2007.  This has led to an expanded program in 2008.  By developing a variety of quality assurance audits and analyses of the data, and by incorporating feedback from volunteers and scientists that are using these data we have made many specific changes in protocols for the 2008 program. Rapidly evolving technologies are providing many new opportunities for innovation in relatively low-cost quality assurance procedures and web-based feedback mechanisms to increase the value and use of these citizen science data.