Estimation by Microcomputer of Interobserver Agreement in Duration Recording of Behaviour

A scheme is presented in which the level of agreement between two observers carrying out duration recording can be more accurately estimated than by conventional procedures. Each observer operates a push-button connected to a microcomputer to signal the presence of the behaviour to be measured and the duration of its occurrence. At the end of the measurement period, the computer reports each observer's rating of the proportion of time for which the behaviour was present, as well as various measures of the level of agreement between observers.