This is already abstracted in IDS annotated bibliography Famine Early Warning and Food Information Systems in the Sahel and Horn of Africa, Lambert et al, 1991, IDS Development Bibliographies 7.
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.