The aim of this paper is to provide PMRT and its subgroups with information about the sampling processes used in surveys conducted under its National Assessment Plan (NAP). The design of national surveys in education in recent years has been strongly influenced by the methodologies used in major international surveys, particularly TIMSS and PISA. In the discussion below, reference will be made to the methods used in these surveys, and their application in the context of Australian national surveys. The intention of this paper is to explain the major steps in the survey sampling process, the reasons for the methods that are used, and some of the consequences of the sampling processes on field operations and in the analysis of the resulting survey data.