The authors of this module gratefully acknowledge the valuable views on this section given by the project colleagues at ILRI and SLU, the university faculty participants of the workshop and first two courses for Africa and by Prof Charan Chantalakhana and Dr John Hodges, previously with FAO, who kindly reviewed the initial manuscript for version 1, and Drs Vijay K. Taneja, Clemens Wollny and Leyden Baker for version 2, for their many constructive suggestions. The AGAP team of FAO, the ILRI-SLU team for capacity building on AnGR, and participants of the workshop held in 2009 in Arusha, Tanzania, are greatly acknowledged for their contributions.