For three years in Bolivia (2002–2005) the INNOVA Project finished researching several technologies for sustainable agriculture, started by earlier DFID-funded projects. Before INNOVA started critics suggested that these technologies should be discarded in favour of a demand survey. Instead, INNOVA kept the existing technologies, but judged the demand for them with several methods (CIAL, sondeo technology fair, and others). INNOVA found that there was demand for some of the technologies, but that a survey would have missed much of the demand, which is implicit. That is, people are not initially aware of all their problems or of all the possible solutions. Over the years, farmers made more specific, sophisticated demands on the technologies, which evolved as a result. Demand and supply of farm technology are like two sides of an unfolding conversation. © 2007 Taylor & Francis Group, LLC.