A synthesis is a written discussion that draws on one or
more sources. It follows that your ability to write syntheses depends on your
ability to infer relationships among sources - essays, articles, fiction, and
also no written sources, such as lectures, interviews, observations. This
process is nothing new for you, since you infer relationships all the time -
say, between something you've read in the newspaper and something you've seen
for yourself, or between the teaching styles of your favorite and least
favorite instructors. In fact, if you've written research papers, you've
already written syntheses. In an academic synthesis, you make explicit the
relationships that you have inferred among separate sources.
A synthesis is based on two or more sources, you will need
to be selective when choosing information from each. It would be neither
possible nor desirable, for instance, to discuss in a ten-page paper on the
battle of Wounded Knee every point that the authors of two books make about their
subject. What you as a writer must do is select the ideas and information from
each source that best allow you to achieve your purpose.