Abstract:
The National Assessment Program: Literacy and Numeracy (NAPLAN) has been a defining feature of the educational landscape in Australia for over a decade. Despite the longitudinal nature of the testing regime and the suitability of NAPLAN data for use in developmental research, few attempts have been made to model developmental patterns of reading or numeracy over all four NAPLAN assessments. In this study we used population data from the state of Victoria to examine trajectories of reading and numeracy development from Year 3 to Year 9. We obtained standardized scores for NAPLAN reading comprehension and numeracy tests for a full cohort of students (n=65,984, Year 3 in 2011) matched at the four assessed grades. The two central aims of the current study were: 1) to identify whether reading and numeracy growth is best defined by linear trajectories or decelerating-curve trajectories; and 2) to test whether Matthew Effects are present in the development of reading or numeracy. The Matthew Effect proposes that students whose initial skills are strong will display steeper growth trajectories over time compared with students whose initial attainment is poor. These differential growth patterns lead to diverging trajectories, and widening of initial achievement gaps over time. The high achievers make the most growth, leaving poor achievers further and further behind. Latent growth curve models were used to identify the best-fitting longitudinal trajectories of reading comprehension and numeracy, and to test whether Matthew Effects characterized development in each domain. For both reading and numeracy, growth was best captured by decelerating-curve trajectories, rather than linear trajectories. That is, as grade levels increased the gain in achievement systematically declined, and this pattern was appropriately captured by the statistical models. Negative intercept-slope correlations for reading and numeracy indicated the opposite of the Matthew Effect: a compensatory growth pattern. Compensatory growth indicates that students with poor achievement at Year 3 have steeper growth trajectories on average compared with their higher achieving peers, and conversely, high achievers in Year 3 make fewer gains to Year 9. Notwithstanding these growth patterns, achievement gaps in academic skills do not completely close between Year 3 and Year 9 and a proportion of students maintain poor reading and maths skills across the middle years of school. These results provide novel insights about basic skills development of Australian students and can contribute additional nuance to debates about how best to support academic development over the compulsory school years.