The success of PISA since its first survey administration in 2000 has attracted an ever increasing number of participating countries. With an increasingly diverse group of countries, the targeting of the original assessment may be less appropriate than when it was first conceived for a smaller more uniform group of countries. The purpose of this paper is to identify the technical issues in respect of Strand C (assessing competencies of those out-of-school) and to discuss and present ways of addressing these issues.