Inductive & Deductive

(  Inductive, Deductive and Abductive methods of teaching )  

Meaning:

     The inductive method of teaching means that the teacher presents the rule through situations and sentences and does guided practice and the learners do free practice, then the teacher deduces or elicits the rule from the learners themselves.

      The deductive method of teaching means that the teacher presents the rule , gives a model then the learners do free practice and answer exercises.          

 Definitions:

Induction:

       From The Oxford English Dictionary (OED); to induce (in relation to science and logic) means “to derive by reasoning, to lead to something as a conclusion, or inference, to suggest or imply,” and induction “as the process of inferring a general law or principle from observation of particular instances.”

Abduction:

    Another version is the “adducing (pulling together) of a number of separate facts, particulars, etc. especially for the purpose of proving a general statement.”

Deduction:

     The OED definition of to deduce is “to show or hold a thing to be derived from etc…” or “to draw as a conclusion from something known or assumed, to infer”;

    Deduction thus is “inference by reasoning from generals to particulars,” or “the process of deducing from something known or assumed…”

Differences:

      Induction and deduction are pervasive elements in critical thinking. They are also somewhat misunderstood terms. Arguments based on experience or observation are best expressed inductively, while arguments based on laws or rules are best expressed deductively. Most arguments are mainly inductive. In fact, inductive reasoning usually comes much more naturally to us than deductive reasoning.

     Inductive reasoning moves from specific details and observations (typically of nature) to the more general underlying principles or process that explains them (e.g., Newton's Law of Gravity).

    The premises of an inductive argument are believed to support the conclusion, but do not ensure it. Thus, the conclusion of an induction is regarded as a hypothesis. In the Inductive method, also called the scientific method, observation of nature is the authority.

    In contrast, deductive reasoning typically moves from general truths to specific conclusions. It opens with an expansive explanation and continues with predictions for specific observations supporting it. Deductive reasoning is narrow in nature and is concerned with testing or confirming a hypothesis.

     Deductive reasoning leads to a confirmation (or not) of our original theories. It guarantees the correctness of a conclusion. Logic is the authority in the deductive method.

Deductive reasoning:

        Deductive reasoning works from the "general" to the "specific". This is also called a "top-down" approach. The deductive reasoning works as follows: think of a theory about topic and then narrow it down to specific hypothesis (hypothesis that we test or can test). Narrow down further if we would like to collect observations for hypothesis (note that we collect observations to accept or reject hypothesis and the reason we do that is to confirm or refute our original theory).

       In a conclusion, when we use deduction we reason from general principles to specific cases, as in applying a mathematical theorem to a particular problem or in citing a law or physics to predict the outcome of an experiment.

Inductive reasoning: 
       Inductive reasoning works the other way, it works from observation (or observations) works toward generalizations and theories. This is also called a “bottom-up  approach. Inductive reason starts from specific observations , look for patterns, regularities (or irregularities), formulate hypothesis that we could work with and finally ended up developing general theories or drawing conclusion.

      In a conclusion, when we use Induction we observe a number of specific instances and from them infer a general principle or law. Inductive reasoning is open-ended and exploratory especially at the beginning. On the other hand, deductive reasoning is narrow in nature and is concerned with testing or confirming hypothesis.

Properties of Deduction

     In a valid deductive argument, all of the content of the conclusion is present, at least implicitly, in the premises. Deduction is non ampliative. If the premises are true, the conclusion must be true. Valid deduction is necessarily truth preserving.

     If new premises are added to a valid deductive argument (and none of its premises are changed or deleted) the argument remains valid. Deductive validity is an all-or-nothing matter; validity does not come in degrees. An argument is totally valid, or it is invalid.

Properties of Induction:

       Induction is ampliative. The conclusion of an inductive argument has content that goes beyond the content of its premises. A correct inductive argument may have true premises and a false conclusion. Induction is not necessarily truth preserving.

View Other Resources:        

1-TILO Project.

2-Active learning 1

3- Active learning 2

5-Critical Thinking 1

6- Critical thinking 2