ENGL210: Technical Writing

Labels, callouts, and captions are identifying text for graphics. Labels and callouts identify specific elements or features on a graphic; whereas captions are short phrases or sentences that describe the graphic. Notes, or footnotes, explain or give credit.

Labels and Callouts 

To identify specific elements or features, labels and captions are placed directly on the graphic or near it. "Although the terms are used interchangeably, labels are text identifers that are self-explanatory in an image, while callouts are labels that require further information outside the image to explain what they are identifying" (Gurak 304). They supplement the visual information. But use them selectively; use them only if readers need them (Rude 116).

The advantage of labels is that the reader gains a basic understanding of elements in the graphic without referring to supplementary explanations. But, too many labels obscure the image. In this case, callouts are the better option. Use numbers or letters to identify each element and the supplementary explanations.

Guidelines for Creating Labels and Callouts

• Determine the number of items to identify in the image (Gurak 308).
• Estimate how much explanation each item requires to determine if labels or callouts are more appropriate (Gurak 308).
• When writing labels and callouts,
  • create a consistent visual style (Gurak 308)
  • use the same terms on the label or callout as in the text (Rude 116)
  • in general, all parts mentioned in the text should have a label or callout, and all parts with a label or callout should be mentioned in the text. (Rude 116)
• Layout the labels or callouts next to the elements in the graphic they identify, using a line to connect the two, if necessary.
  • Use a standard font and size for readability (Rude 116)
  • Align the labels and callouts for a neater appearance (Rude 116)
• If callouts are used, place the explanatory text in a key next to the graphic.

1. Labels
Labels can take different forms (Gurak 304 - 306) -

• they may be placed directly on the graphic (whereby they become part of the graphic), or
• they may be placed around the graphic and use lines to point to the relevant element in the graphic.
• Online, labels can be links or hotspots whereby more information about the element is displayed on mouse rollover.

2. Callouts
Callouts are best used when many parts of the image need to be labeled and each part requires a longer explanation.

The label sequence may be in alphabetical or numerical order. Ensure that the explanation is near the graphic.

Captions 

Captions, tables, and graphics titles must clearly identify information to the reader. Interpretive captions usually require one or more sentences. Captions should be informational, without becoming too lengthy. Captions that are merely a title for a graphic are not very helpful (Franklin 96).

Writing Style for Captions

• Captions for graphics include the title and any explanatory material, immediately under the graphic.
• Words such as Figure, Illustration, and Table should be in bold type.
• The caption should be italicized.
• Treat tables and figures the same.

Good captions are what guide readers not only to see, but also to understand. Captions label graphics with titles and explain to readers what they are seeing, and how to interpret the information captured in the visual. The Franklin Covey Style Guide for Business and Technical Communication provides an excellent source for writing captions (Franklin 39 - 41).

Five Specific Style Rules

• Use interpretive captions whenever possible. Interpretive captions provide both a title and explanatory information,usually expressed in a complete sentence, to help readers understand the central point(s) that the writer wants to convey. A graphic and its caption should be clear and understandable without requiring readers to search for clarifying information in the text:
  • Figure 4. Cabin-Temperature Control System. Constant cabin temperature control is maintained by the system's modulated cabin sensor.
    • This interpretive caption gives the title and then tells the reader the principle message - that the check valve provides near-zero risk. And, it states how the check valve provides near-zero risk (Franklin39).
  • Figure 23. Check Valve. The risk of bad air entering the changer is near zero because the check valve permits air flow in one direction only.
    • This interpretive caption gives the title of the figure and emphasizes that the cabin has a constant temperature - a benefit provided by the feature described in the figure. The caption states clearly what the writer wants the reader to learn from the drawing (Franklin 39).
• Avoid using short, often ambiguous, titles to replace interpretive captions. In the past, styles for technical and scientific documents used only short, simple title captions for visuals. These were often superfluous, providing no real information other than the obvious to the reader, i.e. - A Horse. Titles that are so short and cryptic that they sound telegraphic are not useful. Such captions are only useful when the graphics are self-explanatory, and require no interpretation (Franklin 40).

• Number figures and tables sequentially throughout the document, and place the number before the caption. If an important figure or table is presented twice, treat it as two separate visuals and number each. Figure and table numbers should be whole numbers. (Franklin 40).

• Use periods following interpretive captions but no punctuation following short captions that are not sentences. Interpretive captions are usually complete sentences and should therefore end with a period. Short captions, like titles and headings, are not usually complete sentences, so they require no punctuation (Franklin 41).
  • Captions may appear below or above a visual, but consistency throughout a document is critical. Arguments support both options; choose one, warrant your choice, and be consistent.

• Put the caption above the visual for better visibility when captions are used with slides and other project visual aids. Captions placed at the bottom may be blocked by the heads of those seated in front (Franklin 99).

Notes 

Notes or footnotes are categorized as either explanatory or source notes. Explanatory footnotes are identified by a superscript number or letter. The order in which notes appear is important; explanatory footnotes are placed above source notes. And both are placed above the caption, if the caption is placed at the bottom of the illustration.

Source: Norbert Elliot, http://elliotmedia.wikispaces.com/
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