At the same time, official information on the national tests clearly repeats the message that the national tests only measure a discrete area of student knowledge and skills - providing a snapshot of student achievement in select learning targets - and that supplementary assessments are necessary to fully gauge student process. Research from different countries indicates that while assessment is primarily intended to measure the progress and outcomes of learning, it also has effects on the learning process itself (Somerset, 1996). Several authors have described this influence of assessment on teaching and learning as the “backwash effect” of student assessment (Alderson and Wall, 1993, Baartman et al.,