This paper presents a coding scheme which has been used for the analysis of NLI-dialogues collected by means of Wizard-of-Oz techniques. The scheme covers both dialogue structure and focus structure. Dialogue structure is coded in terms of segments consisting of moves belonging to general fllocutionary types, such as initiative and response, and being further specified as to their topical domains. Focus structure is coded in terms of a number of focal parameters, which may differ from one type of dialogue to another. Relations between values of focal parameters on neighboring discourse segments are determined by a simple model. The coding scheme is flexible and has a high degree of inter rater reliability. It enables comparisons between different types of dialogues and testing of assumed models for dialogue management. A dialogue manager has been implemented that can be customized on the basis of the analysis of a representative set of dialogues from a given application using the coding scheme.