Writing down spoken number words (transcoding) is an ability that is predictive of math performance and related to working memory ability. We analysed these relationships in a large sample of over 25,000 children, from kindergarten to the end of primary school, who solved transcoding items with a computer adaptive system. Furthermore, we…

Task difficulty is a critical issue affecting test developers. Controlling or balancing the item difficulty of an assessment improves its validity and discrimination. Test developers construct tests from the cognitive perspective, by making the test constructing process more scientific and efficient; thus, the scores obtained more precisely…