Each type of chart answers a different goal well: choosing the right one is the first step to communicating data honestly and effectively.

Observation — What to choose

GoalBest chart
show the frequency of categoriesbar chart
show the distribution of a continuous variablehistogram
show the composition of a totalpie (few slices) or stacked bars
compare several distributionsside-by-side box plots
show the relationship between two variablesscatter plot

The guiding principle summarised by Tufte is: “above all else show the data”. Beware of three-dimensional charts, truncated scales, hidden logarithmic axes: all typical ways of lying with statistics.

Topics: Probabilita
Concepts: Rappresentazione grafica dati
Skills: Interpretare grafico