Samuel and Bryant (2)
Piaget's Methods - Conservation Tasks: Piaget devised numerous tests which highlighted the errors children make with certain problems. These errors demonstrated the different quality of thought children have in different stages. The test is known as the conservation experiment. Conservation with beakers of water: If you show a child two beakers of water, one that is tall and thin and the other is short and fat, and you ask the child which beake contains the most water, the pre-operational child (i.e. child under 7) will say the 'tall one', even though they both contain the same amount of water. Piaget argued this was because the child hadn't developed the ability to conserve volume (i.e. the ability to realise something may have the same volume, even though it's in a different shape), which doesn't develop until the child is in the concrete operational stage (i.e. 7-12 years).
Conservation task with clay: Similarly, Piaget said if you roll a piece of clay into a sausage shape, show it to a pre-op child and then roll it into a ball, the child will say the sausage shape has more clay.
Conservation task with counters: If you present a pre-op child a row of 5 counters/buttons spread out and a row of 5 counters/buttons close together, the child will say the spread-out row contains more buttons. Piaget argued, the child's inability to conserve is due to the child's failure to understand that things remain the same (constant) and only the appearnce (how they look) changes. Piaget believed this is an example of centration.The pre-op child hasn't decentred and is therefore, centering on one dimension. e.g. child centres on height of the beaker and fails to take the width into account.