EMC Proven Professional – Data Science and Big Data Analytics — Question 32

The average purchase size from your online sales site is $17, 200. The customer experience team believes a certain adjustment of the website will increase sales.
A pilot study on a few hundred customers showed an increase in average purchase size of $1.47, with a significance level of p=0.1.
The team runs a larger study, of a few thousand customers. The second study shows an increased average purchase size of $0.74, with a significance level of
0.03. What is your assessment of this study?

Answer options

• A. The change in purchase size is not practically important, and the good p-value of the second study is probably a result of the large study size.
• B. The change in purchase size is small, but may aggregate up to a large increase in profits over the entire customer base.
• C. The difference in the change in purchase size between the two studies is troubling; The team should run another, larger study.
• D. The p-value of the second study shows a statistically significant change in purchase size. The new website is an improvement.

Correct answer: A

Explanation

Option A is correct because although the second study shows a statistically significant p-value, the actual increase in purchase size is minimal and may not have practical implications. The other options either misinterpret the significance of the results or suggest unnecessary further studies when the results are already clear.