Inductive vs Deductive reasoning in research

1. Inductive vs
deductive
reasoning
Central Department of Geography
Tribhuvan University
Kathmandu
MPhil/Ph.D. First semester
2079/80

2. What we
will learn?
The biggest difference between deductive and
inductive reasoning is that deductive reasoning
starts with a statement or hypothesis and then tests
to see if it’s true through observation, where
inductive reasoning starts with observations and
moves backward towards generalizations and
theories.

3. Deductive Reasoning

4. Inductive reasoning

5. Deductive
Reasoning
• Use facts, definitions and accepted properties in
logical order to write a logical argument.
• The process of reasoning from known facts to
conclusions. When you reason deductively, you can
say “therefore” with certainty. If your facts were
firm to begin with, then your conclusions will also
be firm.
• Example: Dictionaries are useful books. Useful
books are valuable. Therefore, dictionaries are
valuable.

6. A deductive argument
It is supposed to be a definitive proof of the truth of the claim (conclusion).
 Premise ------------------All men are mortal.
 Premise --------------- Deepak was a man.
 Conclusion ------------ Deepak was mortal.
If the premises are true (and they are), then it simply isn’t possible for the
conclusion to be false.
If you have a deductive argument and you accept the truth of the
premises, then you must also accept the truth of the conclusion.

7. True
premise
True
premise
True
conclusion
+ =
All cats have a keen sense of smell. Fluffy is a
cat, so Fluffy has a keen sense of smell.

8. Deductive Reasoning
The catalog states that all entering
freshmen must take a Philosophy and
Methodology of Geography placement
test.
Conclusion: You will have to take a
Philosophy and Methodology of
Geography placement test.
You are an entering freshman.
Another Example:

9. Inductive reasoning
• Inductive reason starts from specific observations, look for patterns
(or no patterns), regularities (or irregularities), formulate hypothesis
that we could work with and finally ended up developing general
theories or drawing conclusion.

10. An inductive argument
 is one in which the premises are supposed to support the conclusion.
 If the premises are true, it is unlikely that the conclusion is false.
 The conclusion probably follows from the premises.
 Premise ---------------- Deepak was Nepali.
 Premise ---------------- Most Nepalese eat fish.
 Conclusion ------------ Deepak ate fish.
 Even if both premises are true, it is still possible for the conclusion to be false (maybe Deepak was allergic
to fish).
 Words which tend to mark an argument as inductive include probably, likely, possibly and reasonably.

11. True
premise
True
premise
Probably
True
conclusion
+ =

12. Inductive Reasoning
Example:
April has been hot here in Kathmandu. Today is February 26, so it is
going to be another hot day in Kathmandu.
• For 3 weeks, the cafeteria served pizza on Wednesday. I conclude
next Wednesday the cafeteria will have pizza.
• Ramesh noticed that every Tuesday since class started it has rained.
Ramesh thinks it is going to rain next Tuesday.
When we make conjectures based on observations.

13. Summary

15. INDUCTIVE DEDUCTIVE
Inductive approach to research does not have any
place for hypothesis. So, researcher is free to alter
direction of the study.
Deductive approach to research starts with the
hypothesis itself. Researcher is bound not to alter
direction of the study.
Inductive approach is less structured as there is no
guiding factor.
Deductive approach is highly structured because there
is some specific aim to be accomplished.
Inductive approach is appropriate for small sample
project because small numbers of sample are analyzed
with greater gravity.
Deductive approach is appropriate for large sample
project because large numbers of samples are
analyzed with less depth.
Inductive approach is concerned with building a new
theory.
Inductive theory is an approach to research
that starts with the observation and the end
result of the research is THEORY
Deductive approach is concerned with testing an
existing theory.
Deductive theory is an approach to research
that starts with the proposition of hypothesis
and the end result of the research is
Confirmation/rejection.

18. • Deduction has theories that predict an outcome, which are tested by experiments.
Induction makes observations that lead to generalizations for how that thing works.
• If the premises are true in deduction, the conclusion is definitely true. If the
premises are true in induction, the conclusion is probably true.
• Deduction is hard to use in everyday life because it requires a sequential set of facts
that are known to be true. Induction is used all the time in everyday life because
most of the world is based on partial knowledge, probabilities, and the usefulness
of a theory as opposed to its absolute validity.

19. Thank You