Much of the literature on Vocational Education and Training (VET) professional development for teachers and trainers in Australia has been descriptive, outlining the development, construction and outcomes of a range of initiatives or analysing the nature and extend of initial and on-going professional development for teacher sand trainers. There has been little critical analysis of curricula which led to the attainment what has been the most common Australian initial VET teacher/trainer qualification--the Certificate IV in Assessment and Workplace Training, either in terms of the intended or enacted curricula as it was delivered in many hundreds of locations across Australia. This paper addresses this gap. It presents the outcomes of research that examined ways in which learners and processes of learning were constructed, understood and embedded in the delivery of the Certificate IV in Assessment and Workplace Training (AWT). This qualification was delivered from 1998 until November 2006. In late 2004 a new Certificate IV in Training and Assessment (TAA) was introduced, but there was a "teach-out period" of two years on the old qualification. The study involved 16 case studies of registered training organisations that delivered the Certificate IV in AWT. The paper updates the study by examining how the changes associated with the new qualification may affect understandings of learners and learning.