Appendix G: Information Structures--Comparison
In technical writing, comparisons can be very important. Short comparisons
to similar or familiar things can help readers understand a topic better;
comparisons can also help in the decision process of choosing one option
out of a group. An extended comparison, which is the focus in this
section, is one or more paragraphs whose main purpose and structure is
comparison.
Extended comparisons can be informative or evaluative. An
informative comparison seeks to compare the topic to something similar or
familiar to help people understand the topic or, in some cases, to help
people understand both better. An evaluative comparison seeks to
recommend one or more of the options by comparing them. This is the focus
of the types of reports discussed in the section on recommendation reports, feasibility reports, evaluative
reports.
Note: Be sure and check out the examples of comparison
that accompany this chapter:
Identifying Points of Comparison and Requirements
When you write an extended comparison, you must start by identifying the
specific ways in which you are going to compare the things you plan to
write about. These points of comparison are like categories of
comparative detail. For example, in an evaluative comparison of VCRs, you'd
probably want to compare the best four or five machines according to cost,
programmability, reliability, special editing features, and so on. If you
don't start by identifying the points of comparison, your comparison can
become uneven--for example, you might say that VCR Model 1 is easy to
program but not say anything about the programmability of VCR Models 2, 3,
or 4.
In evaluative comparisons, you must also define the requirements, or
the criteria. For example, you might have a maximum cost of $150 for the
VCR. You might want the machine be very easy to program and have good
ratings in terms of its reliability. And you might require that the VCR
have a certain special editing feature. These are all requirements--some
are numerical like cost; some are based on scales such as ease of use; and
some are simple yes/no values--either the machine has the feature or not.
Also for evaluative comparisons, you may have to rank the requirements--the
most important to the least important. In fact, you may have to devise a
statistical method for determining the winning option.
Organizing Comparisons
One of the most important concepts to learn in writing comparisons has to
do with organizing the contents. There are two basic ways to organize a
comparison--the whole-to-whole approach and the point-by-point
approach. To get a sense of how these two approaches work, take a look at
Figure G-12. In the whole-to-whole approach, details about each of the
options being compared are lumped together. This is our natural
tendency--however, it does a sloppy, uneven job of stating the
comparisons. The better way is to use the point-by-point approach. In the
schematic diagram in Figure G-12, you'd have one paragraph comparing the
costs of Models A, B, and C; then another paragraph comparing the
warranties of the three models; and so on.
Use the point-by-point approach unless something about your topic, purpose,
or audience dictates otherwise. With the whole-to-whole approach, the
comparison is often uneven--you might forget to tell about the warranties
for Model B; you might neglect to state the actual results of
comparison--that Model C is better in terms of special features. In the
whole-to-whole approach, writers often leave the actual comparisons up to
the reader, thinking that just supplying the raw data is enough.
In the point-by-point approach, each of the comparative sections should end
with a conclusion that states which option is the best choice in that
particular category of comparison. Of course, it won't always be easy to
state a clear winner--you may have to qualify the conclusions in various
ways, providing multiple conclusions for different conditions.
Figure G-12. Schematic view of the whole-to-whole
and the part-by-part approaches to organizing a comparison. Unless you have
a very unusual topic, use the point-by-point approach.
Figure G-13. Short paragraph-length comparison.
Writing the Comparisons
As with causal discussions, comparisons are not distinctive because of a
certain kind of content. instead, it's the special transitional words that
make comparative writing work: for example, "similar,
"unlike," "more than," "less than," and other
such words that draw readers' attention to comparisons and highlight the
results of the comparisons. Notice how many are used in Figure G-13.
When you write comparisons, take special care to use these transitional
words. Emphasize the similarities and differences--don't force readers to
figure them out for themselves.
Figure G-14. Schematic view of
comparisons. Remember that this is just a typical or common model for the
contents and organization--many others are possible.
Format for Comparisons
Comparisons don't call out for any special format; just use headings,
lists, notices, and graphics as you would in any other technical
document. For details, see:
Return to the table of contents for the TCM1603 Course Guide
(the online textbook for Austin Community College's online
technical writing course).
This information is owned and maintained by David A. McMurrey. For
information on use, customization, or copies, e-mail
davidm@austin.cc.tx.us or call (512) 476-4949.
