Children's Perception of Length

The ability of five‐year‐olds to make relative length judgements and relative number judgements was investigated under three conditions. In one condition the items to be compared were presented simultaneously. In the other two conditions they were presented successively, either with a minimal delay or with a delay of 15 seconds. Children were found to be capable of successful discrimination under all three conditions, though their performance was impaired with a 15 seconds delay. The results are discussed with reference to the distinction between identity and equivalence conservation, and with reference to Brainerd's (1973) transitivity of length task. The latter is claimed to be faulty.