In chapter 6, you learned that a sensitive measure should

1. produce a wide range of scores (so that the measure may capture the wide range of differences in participants)
and
2. do so reliably (so the different scores are not merely due to random error).

Below are buttons that allow you access tp two short simulations that will help you understand how a good measure succeeeds at these tasks (and how a poor measure fails).
After you click a button, move the green slider. As you move the slider, the slider reflects the participants "true" score, whereas the ball reflects what score the insensitive measure would give the participant.