Volume and Heaviness Test
This is a 14-item class task that probes more difficult conservations, including the effect on the level of a liquid in a measuring cylinder when blocks of plasticine and iron of known volume are lowered in, and also density concepts. This is one of the original Piagetian Reasoning Tasks developed in the 1970s when we did a massive national survey to establish the levels of cognitive development of the school population of England and Wales (Shayer and Adey, 1981). Recently Michael Shayer has obtained new representative data on this task which suggests that children’s reasoning ability has dropped dramatically over the past 20 years (Shayer, Coe & Ginsburg, 2007). We can only speculate about possible reasons for this (Adey et al, 2007).