Abstract
Fifty‐six children aged 3;01 to 4;11 years were tested with the standard DCCS task (Frye et al., Cognitive development 10:483–527. 1995) where children have to switch from one sorting dimension (e.g. colour) to another (e.g. shape), and with three variations of this task. The aim was to explore different factors (extra‐dimensional vs. reversal shift and presence of visual clash between target and test cards) that may account for 3‐year olds' executive problems on this task. The only difficult task was the standard DCCS task with a visual clash and an extra‐dimensional shift (mean of 3.55 out of five cards sorted correctly). The three new variations were all much easier (means of 4.6 or higher out of five cards sorted correctly). The difficulty with the DCCS task was particularly pronounced for 3‐year olds when the task was presented first (mean of 0.50 correct) whereas when it followed one or more of the other tasks then children's mean number correct was 4.0 or above. Implications of this finding are discussed for the theory that younger children suffer from an inability to inhibit a predominant sorting strategy and the cognitive complexity and control theory postulating limitations in understanding higher order rules, negative priming of the initially ignored dimension, and children's difficulty in understanding that the change in the task consists in a redescription of the original cards. Copyright © 2002 John Wiley & Sons, Ltd.