It looks at the principles and the methodology employed on a research project in northern Nigeria, which involved the collection of both farm management and nutritional data. The study was a wide ranging one; as such clear decisions about the type of data to be collected was made on the basis of time costs. The use of registered-non registered, continuous - one point and data cores are described and discussed. From these follow the means of sample stratification using these principles. Some ideas for improving RRA are suggested.