Line graphs are the Swiss army knives of data visualisation. They can be almost anything… which is both good and bad.

### Line graphs are slow to interpret

Many graphs serve one clear purpose. Take the five graphs below:

Even without labels, it’s clear what role each of these graphs serves:

- Pie chart—components of a total
- Thermometer—progress toward a goal amount
- Speedometer—percentage of the largest possible value
- Histogram—distribution of values
- Box plot—statistical summaries of several datasets

In other words, if I’m presented with one of the graphs above, I have an immediate head start on interpreting it. If, instead, I’m presented with a line graph, I’m forced to read the axes labels and limits first.

Deciphering text is the slow way to intake information. *Shape* is fastest, then *colour*, and only then *text*. This so-called Sequence of Cognition, popularised by Alina Wheeler, is something marketers need to know about.