Choose a graph
The idea
A graph should match the kind of data and the question. Bar charts compare categories; line charts can show changes across ordered times; dot plots reveal individual numeric observations. Label axes and units. Avoid a display that implies connections the data do not contain.
Worked example
A bar chart can compare favorite fruit counts. A line chart can show daily temperature across a week. Connecting unordered fruit categories with a line suggests a sequence that is not meaningful.
Another application
To compare daily temperatures, label the horizontal axis with ordered dates and the vertical axis with temperature units. For favorite-fruit counts, use separate labeled bars rather than a line suggesting a continuous progression.
A common misunderstanding
Graph type and labels affect interpretation. A visually attractive chart can still fail to answer the question.
Try it yourself
Choose a graph for class survey categories and another for daily measurements. Explain why each format matches its data.
Check your understanding
Which is usually appropriate for comparing counts across categories?
Reveal the explained answer
A bar chart.