Quantitative and data literacy
Interpret percentages, probability, uncertainty and data displays.
What you will learn
- Check units, denominators and comparison groups.
- Distinguish percentage points from percentage change.
- Recognise misleading charts and missing uncertainty.
Before calculating, identify the quantity, unit, time period and denominator. Many errors come from answering a different numerical question from the one asked.
A change from 20 percent to 25 percent is five percentage points and a 25 percent relative increase. State which comparison you are using instead of treating the terms as interchangeable.
Inspect chart axes, omitted categories, sample size and uncertainty. A visually dramatic difference may be small, unstable or created by a truncated scale.