Instructors: This page contains an exercise below for your students to help them learn how to build charts.

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Chart-based graphics are graphics that present numerical information in a non-text form. These forms are likely to be proportional representations of the numbers themselves. These are what many people refer to when they talk about informational graphics.

Chart-based graphics have become highly popular in today’s newspapers. Computer software has made them relatively easy to produce (as we shall see later in this chapter). Many journalists today spend a great deal of time gathering the information that can be presented in charts.

In addition to the principles of accuracy and clarity, informational graphics should share a number of other characteristics. The following are some of those characteristics:

• Simplicity. Graphics can be complex, but their appearance should be uncluttered. One of the criticisms of many graphics is that they are “chartoons” — that is, they have too many little figures and drawings that do not add to the reader’s understanding of the information in the graphic. A graphic should contain the minimum items necessary for understanding the information and the maximum items for good appearance.
  
  
• Consistency. Publications often develop a graphics style just as they adopt a writing style. This style includes rules about what kind of type is used, when color is appropriate, how information is attributed, and a variety of other matters. Like style rules for writing, these rules help both the staff in producing graphics and the reader in understanding them.
  
  
• Attribution. Information in graphics should be attributed, just as information in news stories should be attributed. As with other information in a publication, sometimes the source is obvious and does not need to be specified. In other cases, attribution is vital to the understanding of a graphic.
  
  
• Headlines. Oddly enough, one of the most difficult things about producing an informational graphic is writing its headline. Headlines for graphics do not have to follow the rules of headlines for articles; in most publications, they can simply be labels. They need to identify the central idea of the graphic, however, and this is difficult to do in just a few words. One approach many graphic journalists use to writing a headline for a graphic is to write it before the graphic is built. Doing that gives them the central idea to keep in mind while producing the graphic.

Most charts contain at least the following elements: headline, explainer box, legend, chart, credit line and source. Below is how they can look:

Most mass media publications use three types of chart-based graphics: the bar chart, the line chart, and the pie chart. (There are other types of charts for presenting numerical information such as the scattergraph, but these are not commonly found in the mass media.) Each type of chart is best used for presenting certain types of information and is inappropriate for other types of information. Editors need to understand what charts are appropriate for what types of information.

 

Bar charts

Bar charts are used to compare things.

The bar chart is the most popular type of chart because it is easy to set up, and it can be used in many ways. The bar chart uses thick lines or rectangles to present its information. These rectangles represent the amounts or values in the data presented in the chart. (There are technically two types of bar charts. One uses the name bar chart and refers to charts in which the bars run horizontally. The column chart refers to bar charts in which the bars run vertically. Column charts are more commonly used when time is an element in the data. For the purposes of this text, however, we will not make a distinction between the bar and column chart.)

The two major lines in a bar chart are the horizontal axis, known as the x-axis, and the vertical axis, known as the y-axis. Both should have clearly defined starting points so that the information in the chart is not distorted, particularly the axis that represents the amounts in the graph.

 

Line charts

Whereas the bar chart may show change over time, the line chart must show change over time. It can also show a change in relationships over time. In some instances, it is preferable to the bar chart because it is cleaner and easier to decipher.

The line chart uses a line or set of lines to represent amounts or values, and the x-axis represents time. One of the standard conventions of the line chart is that the x-axis represents the time element and the y-axis represents the amounts or quantities being represented.

Line charts can use more than one line to show not only how one item has changed but the relationship of changes of several items. Data points can be represented by different shapes for each item. The danger with multiple line charts is that too many lines can be confusing to the reader. Graphic journalists should avoid putting more than three lines in a line chart.

 

Pie charts

The pie chart is another popular means of showing data, but its use is specialized. A pie chart should show how an entity or item is divided up, and the divisions are most commonly expressed in percentages that add up to 100 percent. Figures also may be used to identify the parts of a pie chart, but it is important that the creator of a pie chart keep the concept of percentages in mind.

Despite the strict limits of the kind of data that can be shown in a pie chart, this type of chart can be used in a variety of ways. A pie chart can show only one set of data at a time, but several charts can be used together to help compare sets of data, as in the set of pie charts on this page that depict the racial breakdown of populations in three major cities.

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Exercise

Construct a simple chart and informational graphic from each of the following sets of data. The informational graphic should include a headline, chart, explainer box, credit line and source -- just as the examples on this page do.

The sets of data are contained in this downloadable Excel file. We recommend that you use this file and follow the steps in JPROF's Creating charts in Excel to build the graph. After that, the graph can be pasted into a Microsoft Word file to write the headline, explainer box and other text necessary for the completion of the informational graphic.

World’s tallest buildings. When the World Trade Center towers were built in the early 1970s, they were the tallest buildings on earth – each slightly more than 1,360 feet. They were soon eclipsed by the Sears Tower in Chicago. By the time they were destroyed on Sept. 11, 2001, they didn’t even make the top five tallest buildings. Here they are:

World's Tallest Buildings

Taipei 101, Taipei, Taiwan             1,670

Petronas Tower 1, Kuala Lumpur, Malaysia             1,483

Petronas Tower 2, Kuala Lumpur, Malaysia             1,483

Sears Tower, Chicago             1,450

Jin Mao Building, Shanghai   1,381

Source: Council on Tall Buildings and Urban Habitat

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Blood types. Human blood is not created equal. It is classified into four major groups – A, B, AB and O – according to the protein factor found in the blood. Each of these groups has a positive and negative category. Among Americans, the most common blood type is O, but the O types do not constitute a majority. Here is the breakdown of percentage of blood types among Americans:

Blood types            Percentage

O+            37%

O-            6

A+            34

A-            6

B+            10

B-            2

AB+            4

AB-            1

Source: American Red Cross

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Costs of higher education. Total costs for attending public and private colleges and universities has increased substantially in the 1990s. Those increases are continuing in the new decade. This information comes from the U.S. Department of Education, the National Center for Education Statistics, and the Digest of Educational Statistics 2003. The numbers are for 1986 through 2002. These costs are averages for all institutions in these categories.

Year            Public institutions            Private institutions

1986–1987             $3,805                         $9,676

1991–1992             5,138                        13,892

1995–1996             6,256                        17,208

1996–1997             6,530                        18,039

1997–1998             6,813                        18,516

1998–1999             7,107                        19,368

1999–2000             7,310                        20,186

2000–2001             7,586                        21,368

2001–2002             8,022                        22,413

2002–2003             8,556                        23,503

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References

James Glen Stovall, Infographics: A Journalist’s Guide. Allyn and Bacon, 1997.

James Glen Stovall and Edward Mullins, The Complete Editor, Allyn and Bacon, 2005.

Advanced reading material

Harris, Robert L. Information Graphics. New York: Oxford University Press, 2000.

Harrower, Tim. The Newspaper Designer's Handbook. Boston: McGraw-Hill, 2001

 Next: 3 - Maps