Working on the upcoming study on Indicator Development, Selection and Use Principles for Climate Change Adaptation M&E I was reading through a wide selection of adaptation M&E frameworks. After a while I started to notice the different ways in which authors talked about indicators, measures and metrics. The definitions of the terms 'indicator', 'measure' and 'metric' vary across agencies and are often used interchangeably, though there are subtle differences. But what is really the difference between an indicator, measure and metric?!