The correlation between the effort to develop a learning process and early size measures could be used to assess the usability of an employed tool. In particular, when the measures are obtained from the learning process specification and they are relevant effort indicators we can assert that the technical competences of instructional designers are not relevant for the tool usage. We present initial results of applying empirical analysis to confirm a previously usability study performed on the ASCLO-S (Adaptive Self consistent Learning Object SET) editor, a visual language based tool for developing adaptive learning processes.