There has been an increasing focus in recent years on theoretical frameworks to describe cognitive development of statistical concepts. There is now a need to encourage the use of these frameworks to inform practice in the teaching and learning of statistics. This paper focuses on frameworks that describe the levels of cognitive development of the concept of variation. Recent research proposing theoretical frameworks on, or referring to, reasoning about variation are synthesised. Discussion follows on the use of theoretical frameworks to inform the teaching and learning cycle for statistics courses, especially the design of curriculum, learning activities and assessment tasks.