A constant problem for field archaeologists is the need for familiarity with the core concepts of a diverse range of specialist disciplines. Soils and sediments are an integral part of archaeological sites, yet the teaching of soils in archaeology degrees is variable and many archaeologists complain they are lacking in the confidence and skills required to describe and interpret the deposits they excavate. SASSA (Soil Analysis Support System for Archaeologists) is a free-to-use, internet based system designed to familiarise archaeologists with the concepts and possibilities offered by geoarchaeology (the scientific study of soils and sediments). SASSA consists of two core components: the knowledge base and field tool. The ‘front-end’ of the website is the knowledge base; this uses Wiki technology to allow users to add their own content and encourage dialogue between archaeologists and geoarchaeologists. Whilst the field tool uses an XML data structure and decision tree, decision support system to guide the user through the process of describing and interpreting soils and sediments. SASSA is designed for use on both ‘static’ (PC) and ‘mobile’ (PDA and laptop) hardware in order to provide in-situ field support as well as offering office-based ‘reference book style’ help. This article introduces the aims of SASSA, presents SASSA as a user might experience it, and discusses the computing technology used to construct the system.