The Scan is based on a proven, iterative approach to processing hundreds of scientific questions posed by the community through a series of methodical steps to arrive at a prioritized list of the most important and compelling scientific questions. This approach has been successfully used for a wide range of applications which have resulted in highly cited papers that have influenced national priorities for funding and action. There are key steps in the process relative to the core activity which is a physical gathering of experts (the "Retreat"). Pre-Retreat planning includes formation of a diverse and representative International Steering Committee, assembling foundational documents in a database, community-wide solicitations for nominees for Retreat participation and scientific questions, preliminary sorting of questions and recruitment of discussion leaders. At the Retreat the list of 100 most important questions will be embellished within an integrated, substantive narrative.

Horizon Scanning is gaining acceptance as a methodology to develop a collective view of future directions in an area of interest. A seminal paper that guided the development of the 1st SCAR Science Horizon Scan is the paper by Sutherland et al (2011) that analyzes several horizon scan activities and recommends best practice based on these experience. This paper is highly recommended as basic reading for all persons involved in this Horizon Scan:

• Sutherland, W.J., Fleishman, E., Mascia, M.B., Pretty, J. and Rudd, M.A., 2011, Methods for collaboratively identifying research priorities and emerging issues in science and policy, Methods in Ecology and Evolution, 2011, 2, 238–247.

Other examples of the use of Horizon Scanning:

• Sutherland, W.J., et al, 2012, A horizon scan of global conservation issues for 2012, Trends in Ecology and Evolution, vol. 27, no. 1, 12-18
• Sutherland, W.J., et al, 2012, A horizon scanning assessment of current and potential future threats to migratory shorebirds, Ibis, vol. 154, 4, 663-679 - online DOI: 10.1111/j.1474-919X.2012.01261.x
• Sutherland, W.J., et al, 2013, Identification of 100 fundamental ecological questions, Journal of Ecology, 101, 58-67
• Sutherland, W.J., et al, 2013, A horizon scan of global conservation issues for 2013, Trends in Ecology and Evolution, vol. 28, no. 1, 16-22