Page 90 - How to Write and Publish a Scientific Paper, 8th Edition 8th Edition

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Initially, you must analyze your data carefully to determine the clearest, least ambiguous format for displaying the data
so that their information can be quickly grasped by the reader. The graphic format you choose should clarify the
numerical information for the reader by allowing easy comparisons and by conveying the concepts covered in the
associated text. When you select a chart format in DeltaGraph, Excel, or other software program, choose the format
that presents the data most clearly and simply, without unnecessary or confusing design elements. Most graphs used
for scientific descriptions are based on the following types of configurations:
• Bar charts to compare relative proportions and amounts and show trends and changes over time.

• Tables make comparisons of proportions and amounts.

• Pie charts illustrate proportions and show changes over time.

• Line graphs show trends and changes over time.

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• Multi-plot charts display correlations between events. Multi-plot charts can be constructed in the following ways:
(1) by combining line and vertical bar data; (2) by using a double vertical bar graph, with each bar representing two
data sets, one on the bottom and one on top; (3) by using a line chart with individual lines representing each data
variable; or (4) by using a scatter plot with two distributions.
Consistency in Representing Data

The measurement intervals you choose should stay the same throughout the graph. For example, if a time-line graph
represents yearly increments, make each time interval on the x-axis equal to all others, both in measurement and in the
period of time represented. If you are using lines, ensure that each plot line in the graph has the same visual weight as
the others. Vary the visual weight only if you wish to make one particular variable plot in the data set more highly
featured when compared to the others. An alternative is to create lines of equal weight and color, in which each line
uses a different symbol at the node point. Define each data set clearly, either with a legend or by using called-out text
next to each line.
Preparing Graphs for Publication

There are many advantages to creating graphs electronically for publication. One is the ability to work in the final
width specified by the publication for reproduction. Small graphs are usually one column in width; large graphs can be
two columns wide, if necessary. Make sure that all the text is large enough to be read easily but not so large that it
dominates the page and confuses the viewer. Most publications prefer a sans serif typeface such as Helvetica for
labels and captions. Numbers are easier to read and reproduce in a sans serif type. Final type size (if the graph will be
reduced) should be no smaller than 8 points. Boldface type can be used for important labels, such as axis names.

When creating bar graphs, avoid using patterns to differentiate between data sets. Black, white, and two or three levels
of gray usually suffice. When using shades of gray to differentiate the data, use the following percentages: 25, 50, or
75% of black. When your data set

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• Multi-plot charts display correlations between events. Multi-plot charts can be constructed in the following ways:
(1) by combining line and vertical bar data; (2) by using a double vertical bar graph, with each bar representing two
data sets, one on the bottom and one on top; (3) by using a line chart with individual lines representing each data
variable; or (4) by using a scatter plot with two distributions.

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