The 'Linguistic Variation Yearbook 2006' is exclusively devoted to the study of the nature and scope of linguistic variation from the point of view of the minimalist program. In this perspective, the yearbook aims at going beyond the traditional tension between explanatory and descriptive adequacy. It seeks in particular to investigate to what extent the study of linguistic variation can shed light on the broader issue of language particular versus language universal properties and design. The Linguistic Variation Yearbook publishes annually a collection of (invited) articles on a theme that is current in and important to the research on linguistic variation within the generative framework. The focus is on comparative studies, such as research on typology and dialect variation.