I have often encounter confusion on these two terms when talking to molders…
Attribute data has two different outcomes. An example of such an outcome would be a GO / NO-GO gauge which is used when testing parts. This test results in only two different outcomes, Pass or Fail.
Variables are those aspects measured using a scale. An example of this would be a dimension measured using calipers. This device provides a wide variety, or scale, of results based on the accuracy of the instrument and ability of the person taking the measurements.