I'm working with customer satisfaction data on a 1-7 Likert scale with 7 being the "best". I have two distinct response groups, one of which participated in an additional experience and one that did not. The average satisfaction score is higher for the group that participated in the additional experience. I've conducted a Wilcoxon-Mann-Whitney test that indicates that the difference in average satisfaction is statistically significant.
What test is best suited to identify the increase in satisfaction that the additional experience results in? I want to be able to say that "the additional experience results in .5 (or whatever it may be) higher customer satisfaction". This will help us make the best decision for our business.
Please let me know your thoughts and thank you so much for your help!