The principle of proportionality suggests that an organisation’s impact measurement and reporting should be proportional to its size, history, and the complexity of the sector and the outcomes it is working with. Impact measurement is not a laboratory science, and no report will include everything. The purpose of measurement is to be useful to organisations, not to cripple them. A sense of scale is required in relation to the fullness and level of evidence expected from the organisation’s impact reporting, as well as the budget devoted to it.
see measurement system in the impact plan section