Inductive And Deductive Reasoning

1 William Molnar

In inductive reasoning, the reasoning is a bottom-up approach. The observations in inductive reasoning starts with the specific observation and ends with a general conclusion. According to Trochim (2008), the inductive reasoning follows the following format: “observation, pattern, tentative hypothesis, theory”(p 17).Here is a general example of deductive reasoning. Today, I left for work at eight o’clock, and was on time. Therefore, every day that I leave the house at eight o’clock, I will arrive at work on time. The deductive statement is a perfectly logical statement, but does rely upon the initial premise being correct. Perhaps today, there are roadworks, so you will end up being late for work. This is why any hypothesis can never be completely proved, because there is always the scope for the initial premise to be wrong.

Inductive reasoning, while commonly used in science, is not logically valid, because it is not strictly accurate to assume that a general principle is correct. In the above example, perhaps ‘today’ is a weekend, with less traffic. It is illogical to assume an entire premise, just because one specific data set seems to suggest it.

This is not to say that inductive reasoning has no place in scientific processes, because it is an extremely useful tool.

Deductive reasoning it the opposite; the reasoning is a top-down approach. In deductive reasoning, one begins with a general approach and moves to the specific. According to Trochim (2008), the deductive reasoning is the following format: “Theory, Hypothesis, Observation, Confirmation” (p 17).The basic idea is that if something is true of a class of things in general, this truth applies to all legitimate members of that class. The key, then, is to be able to properly

2 William Molnar

identify members of the class. Miscategorizing will result in invalid conclusions.

Examples of deductive reasoning may be both subtle and time-saving. For example, Be careful of that wasp: it might sting. is based on the logic that wasps as a class have stingers; therefore each individual wasp will have a stinger. This conclusion is freeing in that we do not have to examine each and every wasp we ever encounter to ascertain what characteristics it may have. Because of the validity of deductive reasoning, we may make an assumption that is both useful and efficient.There is, however, one major weakness in deductive reasoning, a trap into which a scientist should not fall. Deductive reasoning relies heavily upon the initial premise being correct. If this premise is incorrect, not only does it jeopardize the deductive reasoning, but the whole process of logic

Within my field of education, both forms can be used. In teaching music, I apply both inductive and deductive reasoning to my lessons depending on the concept or topic being taught. For example, when I am teaching my Kindergarten classes a new concept, let’s say rhythm, I apply deductive reasoning. I approach the subject of rhythm in a general nature by exposing the students to various rhythm exercises. I would then begin taking various aspects of rhythm and narrow it down to more specific rhythm patterns. For example, I might concentrate on rhythm in beats of 4 and then concentrate on rhythms in beats of 3.

For inductive reasoning, I would apply it to a possible 8th grade lesson. As an example, if I am teaching the Baroque Period, rather than generalizing about the entire 150 year period and discussing all the various styles and techniques of the period, I would concentrate first by

3 William Molnar

introducing a composer of the period such as Johann Sebastian Bach. Then I would discuss the various styles of music written by Bach and branch out to the general styles of the period. The students would first learn possibly what a Fugue is by concentrating on Bach, then discover Fugue by other composers of the period and then relate the style of the fugue to other general styles of the period such as Canon, Toccata, Variations, etc.

2.Indicate which type of reasoning you are currently favoring for your own dissertation work (and it's OK to think broadly at this point!).

For my own dissertation, I am concentrating on the effects of poverty on school readiness skills in students of high-poverty urban public schools. I feel at this point, the type of reasoning I am favoring is deductive reasoning. I believe that this will benefit my dissertation because I am beginning with a general area, students in high-poverty schools. I am then going to look at specific test scores that would indicate their readiness skills. In this example, I am going from the general to the specific.

Poverty is a very broad and general term. Poverty is a study of an entire society, not just individuals, so that is why I believe this is very general. Once I find the social component of the child, I will then begin to look at his/her performance in school. Now I am looking at individuals. I have now gone to being specific. This is definitely deductive reasoning.