First steps in developing the Dutch version of the Bayley III: Is the original Bayley III and its item sequence also adequate for Dutch children?

The Bayley Scales of Infant and Toddler Development [Bayley III, Bayley, N. (2006). The Bayley scales of infant and toddler development. San Antonio, TX: The Psychological Corporation] is currently developed and exclusively normed for American children. In this study, the appropriateness of the Bayley III item content and item sequence for Dutch children was evaluated. The translated version, the Bayley-III-NL was evaluated in two phases. In phase 1 (N = 100), analyses showed that overall the item content seemed to be appropriate for Dutch children. In addition, the item sequence was found to be suitable for Dutch children. After phase 1, small adaptations were made to the instructions of a few items based on the experiences of the examiners to improve standardization in performance. In phase 2 (N = 400), the findings of phase 1 were confirmed in a larger sample. It is concluded that Dutch norms can be based upon the current version of the Bayley-III-NL.