A Direct Comparison of Two Measures of Ordinal Knowledge Among 8-year-olds

Children’s knowledge of the ordinal relations among number symbols is related to their mathematical learning. Ordinal knowledge has been measured using judgment (i.e., decide whether a sequence of three digits is in order) and ordering tasks (i.e., order the three digits from the smallest to the largest). However, the question remains whether performance on these two ordinal tasks tap into similar cognitive processes. Canadian children (N = 87; Mage = 8.7 years, Grade 3) completed symbolic number tasks (i.e., number comparison, ordering, and judgment), measures of arithmetic fluency (i.e., addition and subtraction) and working memory (i.e., digit backward span). For both ordinal tasks, there was a reverse distance effect for ordered sequences such that children responded faster to adjacent than to non-adjacent sequences (e.g., 2 3 4 vs. 4 7 9) and a canonical distance effect for unordered sequences such that children responded faster to non-adjacent than to adjacent sequences (e.g., 4 2 3 vs. 4 9 7). Working memory and number comparison each predicted unique variance in the ordinal measures (ordering, judgment, and a latent ordinal factor based on the two measures). Furthermore, ordinal skills superseded the role of number comparison as the key predictor of arithmetic, controlling for children’s gender and working memory skills. In summary, although both ordering and judgment tasks index ordinal knowledge, a latent factor that excludes task-specific error may be a better index than either task separately. This project was funded by the Social Sciences and Humanities Research Council of Canada (SSHRC) through an Insight Grant to Jo-Anne LeFevre, Erin A. Maloney, Helena P. Osana, and Sheri-Lynn Skwarchuk. reviewed acceptedVersion