Historically, many of the changes in agricultural technology have been viewed as public goods. It was in the interest of the nation to ensure food production and develop agriculture, and therefore, government funding was often provided to work with farmers in explaining and testing the new technologies. The private sector became important in Europe and the USA with the introduction of mechanical and subsequently chemical technologies. Even so, the impact of public funded extension was undoubtedly significant. Over the last 50 years, there have been a lot of changes in fashion in agricultural extension. Keeping in mind the basic distinction between the ways extension is organised this article focuses on: