Objectives-To identify those important characteristics of doctors' and patients' behaviour that distinguish between ''good'' and ''bad'' consultations when viewed on videotape; to use these characteristics to develop a reliable instrument for assessing general practitioners' performance in their own consultations. Design-Questionnaires completed by patients, general practitioner trainers, and general practitioner trainees. Reliability of draft instrument tested by general practitioner trainers. Setting-All vocational training schemes for general practice in the Northern region of England. Subjects-First stage: 76 patients in seven groups, 108 general practice trainers in 12 groups, and 122 general practice trainees in 10 groups. Second stage: 85 general practice trainers in 12 groups. Main outcome measures-Trainers' ratings of importance; alpha coefficients of draft instrument by trainee, group, and consultation. Results-6890 characteristics of good and bad consultations were consolidated into a draft assessment instrument consisting of 46 pairs of definitions separated by six point bipolar scales. Nine statement pairs given low importance ratings by trainers were eliminated, reducing the instrument to 37 statement pairs. To test reliability, general practitioner trainers used the instrument to assess three consultations. With the exception of one group of trainers, all alpha coefficients exceeded the acceptable level of 0.80. Conclusion-The instrument produced is reliable for assessing general practitioners' performance in their own consultations.
