Lab: Mixed Models

STA 440 Spring 2022 (Jiang)

Labs in STA440 are not graded and they do not count for credit or points.

Introduction

The dataset chocolate.csv in the GitHub repository contains data containing ratings of over 2,500 artisan chocolate bars from around the world, as compiled at (http://flavorsofcacao.com/chocolate_database.html). There is a perception that American chocolate manufacturers are worse than non-American manufacturers. Is there evidence that this is the case in this dataset (based on rating score)?

Hints

Some general considerations:

• There may be non-independence on a variety of levels - for instance, country of origin of the cacao bean, the manufacturer itself, etc. How will you deal with this in your analysis?
• How will you answer the question? Be sure to be clear in your communication.

There may be some data cleaning involved! For the ingredients variable specifically, # is the number of ingredients in the chocolate: B is for beans, S is for sugar, S* is for non-sugar sweetener, C is for cocoa butter, V is for vanilla, L is for lecithin, and Sa is for salt.