The paper reviews the origins and evolution of the Training and Visit (Tamp;V) extension system, which was promoted by the World Bank in 1975-98 in over 50 developing countries. The discussion seeks to clarify the context within which the approach was implemented, and to analyze the causes for...

The paper reviews the literature on the characteristics and impact of opinion leaders on the diffusion of new knowledge, concluding that there is no clear evidence on whether opinion leaders are more effective if they are similar in socioeconomic attributes to the other farmers rather than...