Two experiments were carried out using five subjects to compare
performance using standard and flush fitting rotary controls for electronic
equipment. It vas found that the flush knob could be rotated more quickly
through several revolutions, but a given setting accuracy was achieved less
quickly using this flush knob.
Some of the more general advantages and disadvantages of the flush
knob are outlined.
It should be noted that the primary objective of this study was to
provide the participants with some experience in carrying out Human Factors
studies and the time allowed was not such as to permit a comprehensive
evaluation of the new knob design
