Inductive vs. Deductive Writing

Dr. Tamara Fudge, Kaplan University professor in the School of Business and IT

There are several ways to present information when writing, including those that employ inductive and deductive reasoning. The difference can be stated simply:

• Inductive reasoning presents facts and then wraps them up with a conclusion.
• Deductive reasoning presents a thesis statement and then provides supportive facts or examples.

Which should the writer use? It depends on content, the intended audience, and your overall purpose.

If you want your audience to discover new things with you, then inductive writing might make sense.   Here is n example:

My dog Max wants to chase every non-human living creature he sees, whether it is the cats in the house or rabbits and squirrels in the backyard. Sources indicate that this is a behavior typical of Jack Russell terriers. While Max is a mixed breed dog, he is approximately the same size and has many of the typical markings of a Jack Russell. From these facts along with his behaviors, we surmise that Max is indeed at least part Jack Russell terrier.

Within that short paragraph, you learned about Max’s manners and a little about what he might look like, and then the concluding sentence connected these ideas together. This kind of writing often keeps the reader’s attention, as he or she must read all the pieces of the puzzle before they are connected.

Purposes for this kind of writing include creative writing and perhaps some persuasive essays, although much academic work is done in deductive form.

If your audience is not likely going to read the entire written piece, then deductive reasoning might make more sense, as the reader can look for what he or she wants by quickly scanning first sentences of each paragraph. Here is an example:

My backyard is in dire need of cleaning and new landscaping. The Kentucky bluegrass that was planted there five years ago has been all but replaced by Creeping Charlie, a particularly invasive weed. The stone steps leading to the house are in some disrepair, and there are some slats missing from the fence. Perennials were planted three years ago, but the moles and rabbits destroyed many of the bulbs, so we no longer have flowers in the spring.

The reader knows from the very first sentence that the backyard is a mess! This paragraph could have ended with a clarifying conclusion sentence; while it might be considered redundant to do so, the scientific community tends to work through deductive reasoning by providing (1) a premise or argument – which could also be called a thesis statement, (2) then evidence to support the premise, and (3) finally the conclusion.

Purposes for this kind of writing include business letters and project documents, where the client is more likely to skim the work for generalities or to hunt for only the parts that are important to him or her. Again, scientific writing tends to follow this format as well, and research papers greatly benefit from deductive writing.

Whether one method or another is chosen, there are some other important considerations. First, it is important that the facts/evidence be true. Perform research carefully and from appropriate sources; make sure ideas are cited properly. You might need to avoid absolute words such as “always,” “never,” and “only,” because they exclude any anomalies. Try not to write questions: the writer’s job is to provide answers instead. Lastly, avoid quotes in thesis statements or conclusions, because they are not your own words – and thus undermine your authority as the paper writer.