Displaying data

Rules for figures

Avoid excessive information; use minimal lines; follow journal or textbook protocols; avoid color unless needed; avoid red and green; use an informative, concise caption.

Heading vs. caption

A heading describes a table; a caption describes a figure.

Good headings and captions

Stand alone, explain the gist, usually include what/how/where/when, stay concise, and define all abbreviations.

When to use a table

When actual values are more important than simply showing trends.

Table requirements

Appropriate column headings and subheadings, row labels and sub-labels, and formatting.

Figures

Maps, photographs, scientific drawings or illustrations, and other displays where the image is the most important feature.

Pie chart

Shows how data is spread out; use five or fewer categories, order slices largest to smallest, and do not use 3D.

Bar chart

Shows categorical or qualitative data; categories are on the x-axis and bars have gaps because the data are not continuous.

Bar chart examples

Male vs. female, juveniles vs. adults, or different locations.

Histogram

Shows quantitative, continuous data in value ranges; bars have no gaps and it is useful for describing populations.

Histogram examples

Size classes, length classes, or DBH classes.

Line graph

Shows related values, trends over time or space, rates of change, or multiple dependent variables.

Scatter plot

Shows relationships between two or more variables; each point is one observation and it can illustrate correlation.