=+reported on a test that involved sensing a tiny gap in an otherwise smooth surface by probing with a finger; this functionally resembles many work-related tactile activities, such as detecting scratches or surface defects. When finger probing was not allowed, the sample average gap detection threshold for n1 5 8 normal subjects was 1.71 mm, and the sample standard deviation was .53; for n2 5 10 CTS subjects, the sample mean and sample standard deviation were 2.53 and .87, respectively.