In this paper we build on research reported in the areas of Adaptive Educational Hypermedia and learning styles in order to deal with critical issues influencing the design of adaptation based on the learning style information. In more detail we concentrate on:(i) the different learning style categorizations that have been or could be used for modelling learners’ learning style in the context of an Adaptive Educational Hypermedia System and the way these could guide the design of adaptation,(ii) the adaptation technologies that could better serve learners with different learning styles,(iii) the dynamic adaptation of the system and the diagnosis process including the identification of specific measures of learners’ observable behaviour which are indicative of learners’ learning style preferences.