Most extension impact studies do not consider all aspects when measuring impacts. Most methods used to measure impacts show a statistical relationship between the quantity of extension services made available to farmers and increases in awareness, knowledge, adoption, and productivity. Farmer awareness, knowledge, adoption of technology or practices (AKAP) and changes in farmers' productivity is a convenient method to see the ultimate economic impact of extension. Changes in farmer behaviour will also be reflected in quantities of goods produced, the quantities of inputs used, and in their prices. These, in turn, can be measured as surplus, which is the added value of goods produced from a given set of inputs made possible by the extension activities.

While the AKAP sequence has a natural ordering, resources in the form of skills and activities by both extension staff and farmers are required. Knowledge requires awareness, experience, observation, and the critical ability to evaluate data and evidence. Knowledge leads to adoption, but adoption does not necessarily lead to productivity. Productivity depends not only on the adoption of technically efficient practices but also on infrastructure and marketing. The AKAP sequencing is related to the flow of new technical information, and to the existing state of un-adopted technology. We can see this interrelationship more clearly in the context of productivity "gaps."