Cognitive Development: Conservation of Number

Core Study: Conservation of Number (1952)

Aim: To see at what age a child is able to conserve number

Procedure: Piaget used a cross sectional method in his experiment. This means that it took place at a single point in time and he wanted to gather information rather than controlling a variable over time. He compared the results of children of different ages.

The children were shown, one at a time, two identical parallel rows of counters. The researcher changed the position of the counters while the child watched. They stretched out one row but kept the number of counters the same. The children were then asked which row had more counters in it.

Results: The results showed that the children in the pre-operational stage generally thought that the stretched out row had more counters in it because it was longer. They were unable to conserve the change of the counters. This is because they could not reverse the situation to see that it was the same as before. Children in the concrete operational stage largely got it correct. They said that they both had the same amount of counters. They understood the conservation change.

Conclusion: Piaget concluded that children in the pre-operational stage were unable to conserve as they could not work backwards in the question. As the children got older and more developed, they were able to realise the change in the conservation of number.

Other psychologists, SAMUEL and BRYANT, wanted to find out whether the methodology in Piaget’s experiment was the reason why under seven’s made errors rather than the true lack of information about conservation. They used a larger sample of 252 children, 63 of each aged 5, 6, 7 and 8. They used a laboratory experiment to question the children about the conservation. For this study, they alternated between the mass, number and volume conservation tasks. Instead of the method Piaget used, by asking two questions, they only asked the children one simpler…