Finishing Visualization and Sources of Data

OIS Chapters 1 and 2, Two Links, Grammar of Graphics

Robert W. Walker

2026-02-25

The Basics

LO-E

LO-E

The Dot Plot [it’s really a beeswarm]

from el-erian on X

from el-erian on X

the link

Overview

Scatterplots [Lines just connect points]

Finishing Plots

Important

Prompt: create a scatterplot of returns by assets

Prompt: create a scatterplot of expense ratios and returns with symbols from fees and colors from risk

Important

Prompt: use a checkmark for yes and an X for no as the symbols

plotly

Do’s and Dont’s

The Economist: Mistakes

Steel

Steel

Where do data come from?

Where do data come from?

What does your book have to say?

Where do data come from?

  • Surveys.
  • Macroeconomic aggregates.
  • Sensors and passive collection.
  • Mall intercepts.

Westwood 2025

Bots change the value of survey data.

For Next Time

Read, if you have not already, the CDC Framework, paying particular attention to credible evidence.

What is Goodhart’s Law?

What is Campbell’s Law?