What you'll learn
Types of data and how they are summarised.
Key ideas
- Quantitative (numerical) vs qualitative (descriptive) data.
- Central tendency: mean, median, mode; range for spread.
- Validity (measuring what is intended) and reliability (consistency).
Exam tips
- Choose suitable graphs for the data type.
- Distinguish validity from reliability.
Common mistakes
- Confusing mean, median and mode.
- Mixing up validity and reliability.