An account is given of the overall strategy and measures used in a three-phase study of styles and techniques employed in the initial diagnostic interviews with the parents of children referred to a child psychiatric clinic. The measures of interview style included interviewer activity and talkativeness, directiveness, types of questions and statements, interventions designed to elicit or to respond to feelings, and non-verbal qualities. The informant's response and the interview ‘outcome’ were assessed through measures of the quantity and quality of factual information obtained, and of the extent of expression of emotional feelings by the informant. Good inter-rater reliability was achieved with most measures. Some difficulties were experienced in achieving comparable thresholds for the recognition of expressed emotions.