In an Observation Study,when "Shopping Time in a Supermarket" Is

Multiple Choice

In an observation study,when "shopping time in a supermarket" is defined as: "Using a stopwatch,start the stopwatch the moment the customer enters the store and stop the stopwatch as soon as the customer is handed a receipt by the checkout clerk," this is best described as an example of a(n) :

A) nominal scale
B) equivalent-form scale
C) operational definition
D) test-retest method