Uses of text

Generally text is used to support or complement visual elements. Below are some of the roles text plays:

Title: Concise introduction to the entire presentation
Headings: Concise introductions to sections of the presentation
Body text & Annotations: Sentence-length and paragraph-length blocks of text. I refer to short segments of text associated with graphic elements as "annotations" and longer sections of text that are more independent of the graphic elements as "body text."

In the example below from an infographic about spotting concealed handguns, the text that starts out "Garments worn to conceal..." is body text. It expands on the section heading "CONSPICUOUS CLOTHING." I consider the other text segments annotations because they are clearly associated with the graphics and play the role of making it more clear what the graphic element is trying to show [click on any of the examples on this page to see the full infographic]:

In this next example, the two blocks of text and definitely annotations—they are there to help the viewer interpret the data shown in the charts.

Labels

identity labels: Labels that explain what a graphic element is intended to represent

There are three common strategies used to indicate which label belongs to which graphic element. I refer to these as "association strategies":

proximity: place text as close to the visual element it refers to as possible (this is always good to do, not just to make it clear what the text belongs to, but also so the viewer doesn't have to look away to get the information).
pointers: draw a line from the text to the visual element it refers to
color: make the text the same color as the visual element it refers to (be cautious using this strategy—colored text can be difficult to read and can look unprofessional)

precision labels: Precision labels tell you the precise data value represented by a visual element—e.g. a bar in a bar chart; a wedge in a pie chart; a point on a line graph etc... Think of it this way: the size of the bar, the size of the wedge or the height of the line tell you roughly what the value is, but the precision label tells you precisely what the value is. Precision labels are always numbers.
axis labels: Labels along one of the axes of a chart

EXAMPLES: Figure out which type of labels are presented in each of these examples and which association strategies they use, then look at the note below each to see if your answer is the same as mine.

"Hip" and "Knee" are identity labels (they identify what the lines represent). "619,626" and "407.757" are precision labels (the specify the precise value represented by the data point). "200,000", "400,000" and "600,000" are axis labels (they define the scale of the axis). The labels use proximity and color as association strategies (i.e. you know that "Hip" refers to the green line because it's close to that line and it's the same color of green.

"Beginning of film" "Middle" and "End" function as both axis labels since they define the axis (via proximity), and identity labels since they identify sections of the trailer line (via color). "Start of trailer->" acts an axis title since it defines what the axis is while "0 sec," "30 sec" etc. are axis labels since they define the scale of the axis. The notes at the bottom are annotations. They use lines as an association strategy.

"League average" in the key is an identity label that is associated with the line it refers to via color and also proximity to the short segment of line in the key. "2012 League average" and "League average 1924" are also identity labels. In these cases, they label single data points. The number portion of those labels "7.5" and "2.7" are precision labels since they specific the precisely value of those data points. You could also consider the date portion of those labels a form of precision label, though I see it as part of the identity than the value of that data point. They use proximity and color as association strategies. The gray text are definitely annotations—e.g. "U.S. enters World War I." is not labeling a data point, but adding additional information about that time. There are also axis labels on both the x & y axis.