Educational disadvantage is complex. Former and current conceptions of under-represented (equity) groups only partially capture greater equity and diversity issues. Some students in under-represented categories experience little disadvantage. Others who are not recognised as members of under-represented groups can experience extreme disadvantage. This paper argues that educational disadvantage is a multi-dimensional phenomenon. It examines educational disadvantage in terms of equity and multiple equity overlap. It also examines intra-group differences, arguing for the existence of equity sub-groups as factors which cut indiscriminately across all student populations. Furthermore, the paper discusses the data collection instrument that will more clearly discern gradients of student disadvantage. With this knowledge, educational institutions across the sectors, staff, policy makers and funding bodies will be able to better assist student participation, retention and completions.