Bar chart
Bars of equal width, separated by gaps. Height = frequency. For DISCRETE or categorical data.
Use for. Discrete or categorical data — number of pets, favourite subject, day of the week.
Rules.
- Bars equal width.
- Bars SEPARATED by small gaps (because data is discrete).
- Height = frequency.
- Label both axes; title the chart.
Multi-bar charts. For comparing two categories side-by-side (e.g. boys' vs girls' favourite subjects), draw paired bars with a key.
Worked. Survey of students' favourite sport: football , tennis , cricket , swimming .
- Four bars of equal width, heights .
- Gaps between bars.
- -axis labelled "Frequency", -axis labelled "Sport".
- Discrete / categorical data.
- Bars equal width, with gaps.
- Height = frequency.
- Label axes and title.