Inductive Reasoning
The opposite of deductive reasoning is inductive reasoning, which involves starting with specific details and moving to a larger concluding point or generalization. This short paragraph provides an example of inductive reasoning:
Many college students use laptop computers during class. While some students use their computers to take notes and look up facts related to course discussions, many others use computers to compose emails that aren't related to class, play games, and surf the Internet. Laptop computers must be banned from college classrooms in order to minimize distractions for students.
The writer of the paragraph has arrived at the conclusion by working through specific details and then arriving at the main point.
Evaluating Reasoning
As I noted earlier, a deductive pattern occurs more often than an inductive pattern because deduction involves starting with a topic sentence or main idea and then providing specific support. This more closely matches the general pattern that teachers often look for in student papers.
It's still useful to be familiar with each type of pattern and to understand how main points are supported and reached. Additionally, being able to evaluate an essay for the strength of its reasoning is a good skill to have. You may sometimes be called upon to critique an essay that you've read, and being able to take apart and evaluate something you read can be helpful as you build your own writing skills, too.
When assessing the effectiveness of a piece of deductive reasoning, for example, you should determine first whether there is a clearly expressed main point, which would typically be expressed in a thesis statement at the start (or in a topic sentence if you were looking at a short example like our sample paragraphs from earlier). With deductive reasoning, in addition to offering supporting details after the generalized main idea, the writer will often try to apply the general statement at the start to the specific statements that follow. For example:
In towns where I have lived that have many nice playgrounds, the children are healthier and more active. I have just moved with my child to the town of Grace Point, which has several playgrounds, so I can expect him to be healthy and active.
Consider whether the writer has moved from the general to the specific here. The answer is yes, because the first statement is about towns with lots of nice playgrounds, and the resulting impact on the kids in the area. In the next statement, the writer has applied that first general statement to a specific situation about the writer's own town and own child. So, these statements follow a familiar pattern.
Do you think that this is the most airtight argument, though? Is there a flaw in the writer's reasoning? As you evaluate the reasoning in a paragraph or essay that you read, think about what might be left out in the writer's chain of logic. We know that the town of Grace Point has many playgrounds, but that doesn't automatically lead to a situation in which the writer's child will be active and healthy. If that were the case, we could all be in great shape just by living near a gym, without ever having to go in!
As readers, we would first need to see evidence that the healthy kids in other towns are healthy because they use the playgrounds. We'd also need to see evidence that the writer's child uses the playgrounds in Grace Point regularly and that the specific playgrounds in question are good ones that offer plenty of space to run around and equipment that helps give the kids who visit them good workouts. Developing your skills for spotting problems in the reasoning patterns that you read can help you as you work to avoid the same type of problems in your own writing.