We discuss here the benefit of an automatic assessment technique, recently proposed for multidimensional scoring of children readings. The objective of this research is to monitor the development of reading prosody in a longitudinal study. We recorded 57 children in grade 2, then during their grade 3 while reading the same text. First year recordings were assessed subjectively and used to train the automatic tool. The second year recordings were also assessed both subjectively and automatically. We compare here the results given by the automatic vs. subjective assessment and have a look at the progress of the assessed reading skills of the children: expressivity, phrasing, smoothness and rate.