The Dry and the Wet 1

This paper discusses the relationship between formal, context insensitive information, and informal, situated information, in the context of Requirements Engineering; these opposite but complementary aspects of information are called \the dry" and \the wet." Formal information occurs in the syntactic representations used in computer-based systems. Informal situated information arises in social interaction, for example, between users and managers, as well as in their interactions with systems analysts. Thus, Requirements Engineering has a strong practical need to reconcile the dry and the wet. Following some background on the culture of Computing Science, the paper describes some projects in the Centre for Requirements and Foundations at Oxford. One of these is a taxonomy for Requirements Engineering methods. Another is applying techniques from sociology and sociolinguistics to requirements elicitation, and in particular, to determining the value system of an organisation. These projects draw on ideas from eth-nomethodology and Conversation Analysis. The paper also demonstrates that structures as dry as abstract data types occur in the ordinary discourse of social groups.