Graphs show relationships between data by means of a line, shape, pattern, or series of bars or other symbols for 2 (or more) measures or variables. For example, 2 variables are represented along a pair of axes at right angles. A horizontal (x) axis and a vertical (y) axis intersect at a point called the origin, and are calibrated in the units or categories of the measurement or variable they represent.

Irrespective of the type of graph created, it usually includes:

  • graph title (figure name)
  • axes – quantitative or nominal (categorical)
  • scale, units and categories
  • axis titles
  • plot area or data region
  • encoded data (e.g. dots, bars or lines)
  • trend line or other statistical reference
  • confidence intervals (if necessary) – lines or shading
  • legend
  • notes
  • citation for data source
  • if published online, alternative text for accessibility.

Parts of a graph

This section covers: