Responses to infrequent signals during repetitive work HartnettOonagh 2018 Eight women were employed on repetitive work. Records were made of their rate of production and its variability under different conditions, e.g. times of day, days of week, with and without rest breaks. The length of hand reaction times, in response to rare signals involving an interruption of the work cycle, were measured. Observations were made to see, whether the signal external to the work cycle or whether the next step required within that cycle, evoked the first response depending upon the point of injection of the signal. The results suggest that the capacity, to interrupt the work cycle in response to the rare signal, depends upon its point of injection into the work cycle. A formula has been evolved which expresses a significant relationship between percentage of cycles broken or interrupted and ‘residual movement times’, i.e. the time between the point of injection of the rare signal and the normal completion of the cycle movement. The results also suggest that reaction times and production do vary under the different conditions.