This paper describes the theoretical framework used in interpreting data on runoff and soil loss from field experiments to yield information on soil erodibility. This theory has been employed in the form of computer programs in the field experiments in various tropical countries and Australia which have collaborated in the Australian Centre for International Agricultural Research Project 8551 entitled “The Management of Soil Erosion for Sustained Crop Production”.

The paper also describes common features of the experimental methodology employed in this project, including a description of the set of data management programs employed. These programs are used to retrieve electronically logged data, to field-check, summarise and compile these data in a form suitable for the analysis programs employed.

Subsequent papers in this series illustrate application of the theoretical and experimental methodology outlined in this paper.