Reform and improvement are imperative in the current South African education system. Monitoring of school and learner achievement is an essential for establishing praxis for school improvement. Diversity of culture and South Africa's 11 official languages make it difficult to develop valid monitoring systems. Limited resources, time constraints and the need to redress neglect of large portions of the education infrastructure from the apartheid era make it problematic to develop new monitoring systems for all official languages. Adaptation and translation of existing international monitoring instruments provide alternative solutions to developing new monitoring systems. Adaptation and translation of existing instruments is a daunting process, which balances statistical analysis, translation processes and user and expert evaluations. We investigate how to balance these different processes in order to create an instrument that provides valid data for educational decisions. The processes utilised in the adaptation and translation of the vocabulary subtest of the Performance Indicators for Primary Schools (PIPS) test for the South African context are used to illustrate the complex interplay between user and expert input as well as psychometric rigour. It is hoped this paper will contribute to the development of the necessary instrument adaptation skills in South Africa.