Deductive and Inductive Reasoning
There are two methods of approach in logic: Deductive reasoning and Inductive reasoning. The two methods are used to arrive at a conclusion based on information assumed to be true. Deductive reasoning arrives at a specific conclusion based on generalizations. Inductive reasoning takes events and makes generalizations
Deductive reasoning
Deductive reasoning uses a top-down approach to logic: from general to specific. The starting point is usually a theory followed by a hypothesis, or a definition of a theory which can be tested. Further, we collect observations that finally lead us to be able to test the hypotheses with specific data. The test can lead to confirm or disapprove the hypothesis and theory. Simply put, it is a step-by-step process of drawing conclusions based on previously known truths. So deductive reasoning can be defined as reasoning from stated premises to conclusions necessarily implied by such premises. Deductive reasoning is also called inference.
We use deductive logic a lot in our daily life. For instance suppose you know that bakery shops sell bread and you know X street has bakery shops. So when you have to buy bread you will go to X street and buy bread. Deductive reasoning is used extensively by scientists. One example can be of J. J. Thompson's Cathode Ray-Experiment. Thompson had ideas about how electrons behaved and generated theories about their nature. Therefore, he generated hypotheses, designed experiments and tried to find conclusive answers to add credence to his initial theory.
Inductive reasoning
Inductive reasoning uses a bottom-up approach to logic: from specific to general . The starting point is usually specific observations, followed by detecting patterns and regularities and then a tentative hypothesis is formed (which can be tested) leading to a general theory. Thus, Inductive reasoning can be defined as the process by which a general conclusion is reached from evaluating specific observations or situations.
Charles Darwin’s theory of evolution is an interesting example of use of inductive reasoning. Darwin observed differences in finches on different islands on the Galapagos Islands. He further observed that these populations were geographically isolated from each other and that the variation between the sub-species varied over distance. Using the inductive logic, Darwin proposed that all finches had a common ancestor, but they evolved and adapted, by natural selection. This led to the evolutionary divergence and the creation of new species, the basis of his 'Origin of Species'.
Inductive reasoning and deductive reasoning can work well together in science. Initial theories developed using induction can then be tested using deduction. In some cases where the theory is very complex, induction can result in a valid hypothesis in less time than if deduction were used.
A real life example of inductive reasoning can be crime investigations. A crime investigation begins with gathering evidences left behind by the criminal. It can be anything ranging from a spoon, chair, ring, wallet, finger print the criminal may left can be a clue for the
investigator leading to the possible criminals. After several days of investigating the evidence, the investigator may find the actual criminal. This is an example of inductive reasoning. Let’s see another real life example of inductive logic: Suppose a child puts her hand into a box of toys and withdraws two dolls. She puts her hand again and this time too draws two dolls. By using inductive logic she may conclude that all the toys in the box are dolls.
The difference between deductive and inductive logic is that a deductive argument provides complete proof of the conclusion provided that the premises used are true. An inductive argument can demonstrate only that the conclusion is probably true.
Also, Inductive reasoning is more open-ended and exploratory, especially in the beginning. On the contrary Deductive reasoning is more narrow in nature and is concerned with testing or confirming hypotheses. Most social researches use a combination of both inductive and deductive reasoning to get the best results.
Bibliography Deduction & Induction. (n.d.). Retrieved 2012, from www.socialresearchmethods.com: http://www.socialresearchmethods.net/kb/dedind.php Deductive vs Inductive Reasoning. (n.d.). Retrieved 2012, from www.nakedscience.net: http://www.nakedscience.org/mrg/Deductive%20and%20Inductive%20Reasoning.htm Inducive vs Deductive Reasoning Help. (n.d.). Retrieved 2012, from www.education.com: http://www.education.com/study-help/article/working-arguments/ inductive and deductive reasoning. (n.d.). Retrieved 2012, from www.whatisphilosophy.net : http://www.whatisphilosophy.net/inductive-and-deductive-reasoning Inductive reasoning. (n.d.). Retrieved 2012, from www.experiment-resources.com: http://www.experiment-resources.com/inductive-reasoning.html
