How complex is that sentence? A proposed revision of the Rosenberg and Abbeduto D-Level Scale

We present a revision of the D-Level sentence complexity scale of Rosenberg and Abbeduto (1987). The original scale left some sentences unrated. However, some types of analysis require finding the average D-Level of the sentences in a text. Accordingly, we have generalized the scale so that every sentence receives a score. Further, on the basis of recent psycholinguistic research, we have re-categorized sentences with semi-auxiliaries (e.g., be gonna ) and raising verbs ( seem ). We have also swapped Rosenberg and Abbeduto’s levels 5 and 6, since experimental results show that these levels were originally in the wrong order. Our proposals are motivated by linguistic structure and psycholinguistic data. A brief experiment suggests that the revised scale has better reliability than the original scale.