Multidimensional analysis involves moving away from one-dimensional analyses such as most articulation tests to comprehensive analyses involving levels of phonological information from the word level down to segments. This article outlines one such approach that looks at four levels from words to segments, using nine phonological measures. It also presents a new methodology for comparing children across the levels (multidimensional assessment of phonological similarity (MAPS)), and demonstrates the approach through a comparison of four sibling pairs. The results show that children can differ greatly and unpredictably in their similarities and differences, and that only a multidimensional analysis can identify where these similarities and differences may occur. (Contains 2 tables.)