22. Quiz: What is a p-value Anyway?

QUIZ QUESTION: :

Consider you have implemented a new program in the office to improve company morale. You measure employee morale for each employee via an assessment before and after the program. You want to see if the program was successful. Use this scenario to complete the matches below.

ANSWER CHOICES:

Deciding there was no change in morale, but there actually was an increase.

Deciding the program increased morale, but it actually didn't.

There was no change in the average morale of the company.

The new program on average increased morale.

The probability of the observed change in average morale occurring or an average change even more in favor of an increase in morale given there was actually no change in morale.

Description	Value
Type II Error
Alternative Hypothesis
Type I Error
p-value
Null Hypothesis

SOLUTION:

Description	Value
Type II Error	Deciding there was no change in morale, but there actually was an increase.
Alternative Hypothesis	The new program on average increased morale.
Type I Error	Deciding the program increased morale, but it actually didn't.
p-value	The probability of the observed change in average morale occurring or an average change even more in favor of an increase in morale given there was actually no change in morale.
Null Hypothesis	There was no change in the average morale of the company.

QUIZ QUESTION: :

Using the same example from the first quiz, match each of the below alternative hypothesis with the way the distribution would be shaded. The statistic we compute is the sample mean after the program minus the sample mean before the program .

ANSWER CHOICES:

There is no difference in the average morale.

The average morale after the program is higher than before the program.

The average morale after the program is lower than before the program.

Alternative Hypothesis	Shading
Shade greater than the observed statistic to obtain the p-value.
Shade less than the observed statistic to obtain the p-value.
Shade greater than the positive of our observed statistic and below the negative of our observed statistic to obtain the p-value.

SOLUTION:

Alternative Hypothesis	Shading
Shade greater than the observed statistic to obtain the p-value.	The average morale after the program is higher than before the program.
Shade less than the observed statistic to obtain the p-value.	The average morale after the program is lower than before the program.
Shade greater than the positive of our observed statistic and below the negative of our observed statistic to obtain the p-value.	There is no difference in the average morale.