How do I create figures and tables?
Overview of illustrations
Is one picture really worth 1,000 words? Yes and no. Illustrations (figures and tables) play a major role in highlighting and clarifying results and data. Appropriate, well-drawn illustrations can substantially increase your readers’ comprehension and can convey trends, comparisons, and relationships more clearly and concisely than text alone. Yet even the best illustrations need textual support because the conclusions that you may draw from your results are not always obvious to your audience. Illustrations must be supported by captions and text that guide the reader’s interpretation of the data.
In technical writing, there are two types of illustrations: figures and tables. Anything that is not a table is considered a figure—no matter what form it takes. Figures include drawings, graphs/charts, photographs, maps, etc. Technical writers differ in their use of terminology for illustrations. Fig. 1 shows the terminology used in this website:
Figure 1: An organization chart showing the terminology for ChE technical illustrations.
1. Identify all illustrations as either tables or figures. Do not use the words “chart,” “exhibit,” “graph,” or “photo,” when naming a specific figure.
2. Always place the illustration as close as possible to the text that describes it. Place the explanatory text first and the illustration second.
3. Keep all illustrations consistent in font size, typeface, symbol size, and line weight.
4. Allow enough white space around and within the illustration for easy viewing.
5. In APA style, the label “Figure” is italicized (Figure 1). “Table” remains in Roman font (Table 1).
6. Place figure numbers and captions directly below figures. Place table numbers and titles directly above tables. Use Arabic numbers to label both figures and tables (Figure 1, Figure 2, etc; Table 1, Table 2, etc.).
7. Whenever you refer your reader to a figure in the text portion of your paper, the word “Figure” should be capitalized and abbreviated, e.g., “see Fig. 6.” The word “Table” is also capitalized, but not abbreviated, e.g., “see Table 7.”
8. Make sure you integrate the illustration with the textual discussion. Refer to each illustration in the text by saying, “see Fig. 1” or “see Table 1”). In the text, give directions for reading and interpreting the data. Draw conclusions about the illustration. Do not expect your reader to look at the illustration and draw the same conclusions that you did.
1. Each illustration must have a number and a caption. Number the figures and tables consecutively throughout the text. Keep the information as brief and simple as possible. Figures and tables are numbered separately. Therefore, Table 5 could appear in a document after Figure 20.
When illustrations are less important to your explanation, they may be located in an Appendix. In this case, they are numbered as Figure A-1, Figure A-2, etc.
2. The caption should be understandable without reference to the text. At the same time, make sure that the wording in the caption is consistent with the wording of the text. Never add new ideas or new interpretations to the caption.
Capitalize the first word and proper nouns in captions.
3. Standard abbreviations are permissible when adding labels, legends, and captions.
4. Illustrations should be uncluttered. Put keys to acronyms in the caption. If you are creating a graph, your software may generate keys to symbols in a corner of the plot. This format is acceptable as long as the key is clearly distinguished from the curves.
5. List data sources or references for your figures in the caption of your illustration: (Bureau of the Census, l990). If you need to modify the original illustration, indicate that you have done so: (Bureau of the Census, 1990, modified by the authors).
6. Both figures and tables should be listed as they occur in the Table of Contents section of your report. Make sure that your captions and page numbers correctly correspond to those listed in your Table of Contents.
1. Tables are expressed in tabular form and should be kept separate from figures. Tables should supplement, not duplicate, text and figures. Use tables for the following situations:
(a) when the data are precise numbers that must be presented
(b) when there are too many numbers to be presented clearly as text or
(c) when more meaningful interrelationships can be conveyed in a table.
2. The title should always be placed at the top of the table and it should identify the main point. Do not place any punctuation after the title. Name the independent variable (the group you are discovering information about) in the heading of the left-hand column. Name the dependent variables (the categories you are comparing) in the column heads.
Example: In a table of weather conditions, the independent variable would be the months of the year. The dependent variables would be average temperature, average precipitation, etc.
3. Every column must have a heading that describes the material below it. Keep headings to two lines, and use standard abbreviations and symbols. Try to keep the entries parallel and of consistent length. Define nonstandard abbreviations in footnotes.
A graph can present the same statistical data as a table, but in a way that emphasizes trends and characteristics. Remember that a graph is a “figure,” so follow the guidelines for presenting figures.
• Scatter Graphs—use to illustrate a correlation, when the data show a degree of variability.
Example: The number of hurricanes to the average temperature.
• Line Graphs—use to demonstrate a trend or a relationship.
A trend shows the same data changing over time.
Example: The population figures for one city at different points in time.
A relationship shows the interaction of two variables.
Example: The percentage of pollutant to the size of a filter.
• Bar Graphs—use to compare sets of data. Bar graphs are useful for clarifying data for non-technical or general science/engineering audiences.
Example: The population of three different cities at one point in time.
• Pie Graphs—use to show discrete values as parts of a whole.
Example: The deductions from a paycheck.
Charts illustrate structure or sequencing. Remember that a chart is a “figure,” so follow the guidelines for presenting figures.
• Organization charts—use to show the structure of a department, a company, or other organization.
• Flow charts—use to show a process
Example: Examples from Rube Goldberg
• Gantt charts—use to show a schedule