Armand Conducts a Study for His Research Method Class

question 24

Essay

Armand conducts a study for his research method class. He is curious as to whether watching romantic movies makes people more committed to their romantic relationship. He collects a sample of men in dating relationships and divides them into two groups. One group watches a 5-minute clip of a movie in which the main characters are having a romantic first date. The second group watches a 5-minute clip from the same movie in which the main characters break up. After the participants watch the movie clip, they are then asked to write a sentence about their relationship. Armand counts the number of uses of the words we and us as a measure of commitment. After conducting the study, he finds that there is not a statistically significant difference between his two groups.
Armand's professor suggests that the null effect may be due to a large amount of within-group variance. State three causes of within-group variance in Armand's study.

---

Definitions:

Sample Means

The average value calculated from a sample of a population.

Centerline

In statistics, the centerline often refers to the median value in a dataset or the middle line in a control chart that represents the average level of performance.

Process Capability Index

The process capability index is a statistical measure that quantifies how well a process can produce output within specified limits compared to the allowable spread of specification limits.

Specification Limits

Specification limits are defined boundaries within which a product or process measure is considered acceptable according to customer or regulatory standards.