Compare and rank
Diverging bar chart
Shows positive and negative values on opposite sides of a reference.
- Chart
- Deviation
- Comparison
What it answers
Which values lie above or below the reference?
- Shape
- Bars around a reference line
- What it shows
- Direction and magnitude of deviation.
Example
The question
Which teams are over or under their headcount plan?
Headcount against plan by team (people)
Illustrative data. It belongs to no company.
When to use it
Use it when
Showing signed values, gains/losses or differences from a baseline.
Avoid it when
When positive and negative signs have no meaningful interpretation.
How to read it
Locate the reference line, then compare direction and distance from it.
The data you need
- Layout
- Long table
- Fields
- Category: text; Value or Difference: signed number
- One row is
- One category and a signed difference from a stated reference. What is the grain?
- Rules
- Define the reference and units. If supplying actual and reference values, calculate their difference.
- Optional
- Alternative columns: Category,Actual,Reference.
- Preparation
- Validate the input grain and missing values. Define the reference and units. If supplying actual and reference values, calculate their difference.
- Units
- Use the measured variable's stated unit consistently. No denominator is implied unless the value is a rate or proportion.
Worked example
Data A=-8, B=12, C=3 relative to zero. A is below the reference; B is 12 units above it.
| Category | Difference |
|---|---|
| A | -8 |
| B | 12 |
| C | 3 |