The Halo Effect refers to the tendency for positive impressions of brands or products in one area to positively influence people's opinions or feelings in other areas. For example, if a picture of a product makes it look aesthetically pleasing (i.e., prettier), then people will assume - based on an unfounded belief - that the product is also more useful. A team at Amazon wants to test this theory in their customers, so they run a study with n = 250,000 - they find that making the pictures of their products on their website look more aesthetically pleasing increases the likelihood that they will purchase the product compared to other similar products, with an associated p-value that is <.01 and an effect size of d = 0.002.

a) Describe how the sample size of this study may have contributed to both the statistical and practical significance observed.

b) What is the statistical and practical significance of this difference (assume = .05)? How do you know?

c) Your friend runs an online store that sells office supplies on Amazon's website. She hears this claim in a TV interview with the CEO of Amazon and thinks that she should hire an expensive photography studio to take new pictures of all her products so that they will be more likely to sell. Given the statistical and practical significance of this difference, how would you tell her to interpret this claim?