# Projections and Normalization

## What Problem This Solves

This reference covers two of the most common technical sources of cartographic distortion.

## When to Use It

Use this when projecting geographic data or choosing how mapped values should be normalized.

## Key Takeaways

- Projection choice affects area, distance, and direction reading.
- Choropleths often require normalization by population, land area, or another denominator.
- Equal-looking regions can hide radically different population or measurement context.

## Common Mistakes

- Treating raw counts as choropleth-ready.
- Ignoring what the projection emphasizes or distorts.

## Adjacent Skills

- `../SKILL.md`
- `../../statistical-and-uncertainty-visualization/SKILL.md`

## Source Links

- [D3 geo projections](https://d3js.org/d3-geo/projection)