"Outcome harvesting is a monitoring and evaluation methodology used to identify, describe, verify and analyse the changes brought about through a development intervention. It is designed to collect evidence of change, and then work backwards to assess contribution to that change. It was partly inspired by Outcome Mapping, and the two are often seen as complementary methodologies." (Introduction)

Outcome harvesting is considered most useful under three conditions:
- It is appropriate when the focus is mostly on outcomes rather than activities or outputs. Outcome harvesting is designed to help assess what changed and why, in order to help understand change processes. It is not designed to assess whether or not activities were carried out according to plan.
- Outcome harvesting is designed for use in complex situations where the relationship between cause and effect is not fully understood and/or where many different actors influence change. In these contexts the desired changes, and the activities carried out in order to achieve them, are often highly unpredictable, and plans need to be constantly modified over time. Outcome harvesting is particularly useful in areas of work such as policy influencing, mobilisation, capacity development, empowerment and network development.
- Outcome harvesting is appropriate when the purpose of an M&E exercise is to learn about change in order to improve future performance. It is considered most useful when different stakeholders want not only to identify change, but also to learn about how and why those changes were brought about." (Page 1-2)