Suppose that we have a variable 'footspeed', with values [slow, medium, fast].  By which of the following procedures could we measure 'footspeed'?
1
Have you run for 20 yards, and make a subjective judgment of whether you are slow, medium, or fast.
Have you run for 40 yards, record the time on a stop watch, and record the number of seconds rounded to the nearest tenth as the value for 'footspeed'.
Have you throw a dart at a board that has three areas: 'slow', 'medium', and 'fast'.  Record the area in which the dart landed as the value for 'footspeed'.
Have you run for 40 yards, record the time on a stop watch, and record 'slow' if your time exceeded or equalled 6 seconds, record 'medium' if your time was less than 6 seconds but exceeded or equalled 4.8 seconds, and record 'fast' if your time was equal to or less than 4.8 seconds.