Introduction to work sampling

Points out that single or unsystematical observations may give quite erroneous ideas of how efficiently a worker is employed. Explains the “random” concept in statistics, using a bowl of 10,000 marbles of two colors. Applies the random sample method to a model of a machinist’s working day. Presents the claim that work sampling can provide many results of stop-watch time-and-motion study: standard hours of production work; average performance index; indication of idle time and delay causes.