Chapter 3, Problem 3EA

For each of the following operational definitions, decide whether you consider it to be a valid measure. Explain why or why not. Decide whether you consider it to be a reliable measure. Explain why or why not.

1. A researcher defines academic motivation in terms of the number of minutes a student spends working on class-related material outside of class during a 24-hour period from noon on Monday to noon on Tuesday.

A professor classifies students as either introverted or extroverted based on the level of participation in class discussions during the first week of class.

A sports psychologist measures physical fitness by measuring how far each person can throw a baseball.

Reasoning that bigger brains require bigger heads, a researcher measures intelligence by measuring the circumference of each person’s head (just above the ears).