Module 9 Data Visualization and Data Exploration

by Patrick Boily, with contributions from Ehssan Ghashim and Maia Pelletier


Why do we display evidence in a report, in a newspaper article, or online? What is the fundamental goal of our charts and graphs? Representation data properly, in a manner that will allow an audience to gain insight about the underlying situation, is, without a doubt, the most important skill a quantitative consultant must possess. In this chapter, we introduce some commonly-used charts, discuss the fundamental principles of analytical designs, give a brief overview of dashboards, and present the important notions of the grammar of graphics and its implementation in ggplot2.

Contents

9.1 Data and Charts
     9.1.1 Pre-Analysis Uses
     9.1.2 Presenting Results
     9.1.3 Multivariate Elements in Charts
     9.1.4 Visualization Catalogue
     9.1.5 A Word About Accessibility

9.2 Principles of Analytical Design
     9.2.1 Comparisons
     9.2.2 Mechanism, Structure, Explanation
     9.2.3 Multivariate Analysis
     9.2.4 Integration of Evidence
     9.2.5 Documentation
     9.2.6 Content First and Foremost

9.3 Introduction to Dashboards
     9.3.1 Dashboard Fundamentals
     9.3.2 Dashboard Structure
     9.3.3 Dashboard Design
     9.3.4 Examples

9.4 Basic Visualizations in R
     9.4.1 Scatterplots
     9.4.2 Barplots
     9.4.3 Histograms
     9.4.4 Curves
     9.4.5 Boxplots
     9.4.6 Examples

9.5 ggplot2 Visualizations in R
     9.5.1 Basics of ggplot2’s Grammar
     9.5.2 ggplot2 Miscellenea
     9.5.3 Examples

9.6 Exercises