RESUMEN
An accurate method of recording the frequencies of copulatory events, the latencies of initiation to copulation and the time spent in different behavioural categories is described. A microcomputer (IBM-PC) based data collection system for acquisition and analysis of male rodent sex behaviour has been developed. This software features ease of data entry and operation, using single key presses by assigning a preset code to each. Internal clock of the computer is made to function as a timer for accurate recording of latencies and intervals. A print out of the frequency or duration of data can be obtained either concurrently or after the completion of the experiment, as required. The least count of the technique is about 10(-4) min and this precludes its use for extremely rapidly changing behaviour.