From: Subject: Deduction & Induction Date: Fri, 26 Mar 2010 10:26:33 -0500 MIME-Version: 1.0 Content-Type: multipart/related; type="text/html"; boundary="----=_NextPart_000_0000_01CACCCE.CE99B6B0" X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 This is a multi-part message in MIME format. ------=_NextPart_000_0000_01CACCCE.CE99B6B0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Content-Location: http://www.socialresearchmethods.net/kb/dedind.php Deduction & = Induction
=20

SEARCH:
=20

=AB PreviousHomeNext=20 =BB

Home =BB = Foundations =BB Philosoph= y of=20 Research =BB

# Deduction & Induction

## Deductive and Inductive Thinking

In logic, we often refer to the two broad methods of reasoning as the = deductive and = inductive=20 approaches.

Deductive reasoning works from the more general to the = more=20 specific. Sometimes this is informally called a "top-down" approach. We = might=20 begin with thinking up a theory about our topic of interest. We = then=20 narrow that down into more specific hypotheses that we can = test. We=20 narrow down even further when we collect observations to = address the=20 hypotheses. This ultimately leads us to be able to test the hypotheses = with=20 specific data -- a confirmation (or not) of our original = theories.

Inductive reasoning works the other way, moving from = specific=20 observations to broader generalizations and theories. Informally, we = sometimes=20 call this a "bottom up" approach (please note that it's "bottom up" and=20 not "bottoms up" which is the kind of thing = the=20 bartender says to customers when he's trying to close for the night!). = In=20 inductive reasoning, we begin with specific observations and measures, = begin to=20 detect patterns and regularities, formulate some tentative hypotheses = that we=20 can explore, and finally end up developing some general conclusions or=20 theories.

These two methods of reasoning have a very different "feel" to them = when=20 you're conducting research. Inductive reasoning, by its very nature, is = more=20 open-ended and exploratory, especially at the beginning. Deductive = reasoning is=20 more narrow in nature and is concerned with testing or confirming = hypotheses.=20 Even though a particular study may look like it's purely deductive = (e.g., an=20 experiment designed to test the hypothesized effects of some treatment = on some=20 outcome), most social research involves both inductive and deductive = reasoning=20 processes at some time in the project. In fact, it doesn't take a rocket = scientist to see that we could assemble the two graphs above into a = single=20 circular one that continually cycles from theories down to observations = and back=20 up again to theories. Even in the most constrained experiment, the = researchers=20 may observe patterns in the data that lead them to develop new theories. =

=AB PreviousHomeNext=20 =BB

Copyright =A92006, William M.K. Trochim, All Rights = Reserved
Purchase=20 a printed copy of the Research Methods Knowledge Base
Last = Revised:=20 10/20/2006