Inductive reasoning Reasoning Causal inference Categorical inference Reasoning by analogy Types of inductive reasoning

1. INDUCTIVE
REASONING
Shamna Ts
MSC. CLINICAL PSYCHOLOGY

2. INDUCTIVE REASONING
CAUSAL INFERENCES
CATEGORICAL INFERENCES
REASONING BY ANALOGY
TYPES OF INDUCTIVE REASONING

3. REASONING
• Reasoning is a cognitive activity in which we transform information in order to reach
specific conclusions.
• Reasoning is the process of drawing conclusions from principles and from evidence
(Leighton, 2004a, 2004b; Leighton & Sternberg, 2004; Sternberg, 2004; Wason &
Johnson-Laird, 1972). In reasoning, we move from what is already known to infer a
new conclusion or to evaluate a proposed conclusion.
• Reasoning is divided into two types :
Deductive reasoning
Inductive reasoning

4. Inductive Reasoning
• Inductive reasoning is a logical process in which multiple premises, all believed true or found
true most of the time, are combined to obtain a specific conclusion or to supply evidence for
the truth of a conclusion.
• Inductive reasoning is a specific-to-general form of reasoning that tries to make
generalization based on specific instances.
• Inductive reasoning is often used to generate predictions or to make forecasts.
• Inductive reasoning differs from deductive reasoning in that while the conclusion of a deductive
inference is certain, the truth of the conclusion of an inductive inference is only probable, where
the degree of certainty is based upon the strength (or consistency) of the evidence.
• In other words, the conclusion of an inductive inference is not a logical certainty (such as when a
meteorologist predicts snow). Inductive reasoning also encompasses most cases of where a
general principle is derived or where categories are formed based on specific observations
(provided that they are probabilistic in nature).

5. • Inductive reasoning, which involves making a generalized conclusion from premises (statements)
referring to particular instances. A key feature of inductive reasoning is that the conclusions of
inductively valid arguments are probably (but not necessarily) true.
• Eg : The left handed people I know are writers; therefore, all left handed people are writers .

6. • Inductive Reasoning is a “bottom-up” process of making generalized assumptions based on
specific premises. Inductions are usually made at a subconscious level, but they play an
integral role in our actions and beliefs. For example, an induction could state that everybody at
a party was wearing blue shirts, Laura was at the party, therefore she was wearing a blue
shirt.
• Here are some examples of inductive reasoning:
• Data: I see fireflies in my backyard every summer.
Hypothesis: This summer, I will probably see fireflies in my backyard.
• Data: I tend to catch colds when people around me are sick.
Hypothesis: Colds are infectious.
• Data: Every dog I meet is friendly.
• Hypothesis: Most dogs are usually friendly.

7. CAUSAL INFERENCES
• Causal inferences-how people make judgments about whether something causes something
else.
• A causal inference draws a conclusion about a causal connection based on the conditions of
the occurrence of an effect. Premises about the correlation of two things can indicate
a causal relationship between them, but additional factors must be confirmed to establish the
exact form of the causal relationship.
• causal inference, one reasons to the conclusion that something is, or is likely to be, the cause
of something else. For example, from the fact that one hears the sound of piano music, one
may infer that someone is (or was) playing a piano. But although this conclusion may be likely,
it is not certain, since the sounds could have been produced by an electronic synthesizer.

8. • One of the first investigators to propose a theory of how people make causal judgments was John
Stuart Mill (1887). He proposed a set of canons-widely accepted heuristic principles on which people
may base their judgments.
• For example, one of Mill's canons is the method of agreement. It involves making separate lists of the
possible causes that are present and those that are absent when a given outcome occurs. If, of all the
possible causes, only one is present in all instances of the given outcome, the observer can conclude
inductively that the one cause present in all instances is the true cause. That is, despite all the
differences among possible causes, there is agreement in terms of one cause and one effect.
• For example, suppose a number of people in a given community contracted hepatitis. The local health
authorities would try to track down all the various possible means by which each of the hepatitis
sufferers had contracted the disease. Now suppose it turned out that they all lived in different
neighborhoods, shopped at different grocery stores, had different physicians and dentists, and
otherwise led very different lives but that they all ate in the same restaurant on a given night. The
health authorities probably inductively would conclude that they contracted hepatitis while eating at
that restaurant.

9. • Another of Mill's canons is the method of difference. In this method, you observe that all the
circumstances in which a given phenomenon occurs are just like those in which it does not occur
except for one way in which they differ.
• For example, suppose that a particular group of students all live in the same dormitory, eat the same
food in the same dining halls, sleep on the same schedule, and take all the same classes. But some of
the students attend one discussion group, and other students attend another. The students in
discussion group A get straight As. But the students in discussion group B get straight Cs. We could
conclude inductively that something is happening in the discussion groups to lead to this difference.
Does this method sound familiar? If the observer manipulated the various aspects of this method, the
method might be called an empirical experiment: You would hold constant all the variables but one.
You would manipulate this variable to observe whether it is distinctively associated with the predicted
outcome.

10. Categorical Inferences
• On what basis do people draw inferences? People generally use both bottom-up strategies
and top-down strategies for doing so (Holyoak & Nisbett, 1988). That is, they use both
information from their sensory experiences and information based on what they already know
or have inferred previously.
• In a categorical inference, one makes a judgment about whether something is, or is likely to
be, a member of a certain category. For example, upon seeing an animal one has never seen
before, a person with a limited knowledge of dogs may be confident that what he is seeing is a
dog but less certain about the specific species

11. • Bottom-up strategies are based on observing various instances and considering the degree of
variability across instances. From these observations, we abstract a prototype.
• Once a prototype or a category has been induced, the individual may use focused sampling
to add new instances to the category. He or she focuses chiefly on properties that have
provided useful distinctions in the past.
• Top-down strategies include selectively searching for constancies within many variations and
selectively combining existing concepts and categories

12. Reasoning by Analogy
• Inductive reasoning may be applied to a broader range of situations than those requiring
causal or categorical inferences. For example, inductive reasoning may be applied to
reasoning by analogy.
• Consider an example analogy problem: "Fire is to asbestos as water is to (a) vinyl, (b) air, (c)
cotton, (d) faucet." In reasoning by analogy, the reasoner must observe the first pair of items
("fire" and "asbestos" in this example) and must induce from those two items one or more
relations (in this case, surface resistance because surfaces coated with asbestos can resist
fire).
• The reasoner then must apply the given relation in the second part of the analogy. In the
example analogy, the reasoner chooses the solution to be "vinyl" because surfaces coated
with vinyl can resist water. Some investigators have used reaction-time methodology to figure
out how people solve induction problems.

13. • For example, using mathematical modeling I was able to break down the amounts of time
participants spent on various processes of analogical reasoning. I found that most of the time
spent in solving simple verbal analogies is spent in encoding the terms and in responding
(Sternberg, 1977).?)
• Only a small part actually is spent in doing reasoning operations on these encodings. The
difficulty of encoding can become even greater in various puzzling analogies. For example, in
the analogy RAT : TAR :: BAT : (a. CONCRETE, b. MAMMAL, c. TAB, d. TAIL), the difficulty is
in encoding the analogy as one involving letter reversal rather than semantic content for its
solution.
• In a problematic analogy such as AUDACIOUS : TIMOROUS :: MITIGATE : (a. ADUMBRATE,
b. EXACERBATE, c. EXPOSTULATE, d. EVISCERATE), the difficulty is in recognizing the
meanings of 5 20 Chapter 12 • Decision Making and Reasoning the words.
• If reasoners know the meanings of the words, they probably will find it relatively easy to figure
out that the relation is one of antonyms. (Did this example audaciously exacerbate your
difficulties in solving problems involving analogies).

15. Examples: Inductive reasoning
Stage Example 1 Example 2
Specific observation Nala is an orange cat and she
purrs loudly.
Baby Jack said his first word at
the age of 12 months.
Pattern recognition Every orange cat I’ve met purrs
loudly.
All observed babies say their
first word at the age of 12
months.
General conclusion All orange cats purr loudly. All babies say their first word at
the age of 12 months.

16. TYPES OF INDUCTIVE REASONING
1. Generalization
• A form of inductive reasoning that draws conclusions based on recurring patterns or repeated
observations.
2. CASUSAL INFERENCES
• Causal reasoning is a form of inductive reasoning we use all the time without ever thinking
about it. If the street is wet in the morning, you know that it rained based on past experience.
Of course, there could be another cause—the city decided to wash the streets early that
morning—but your first conclusion would be rain. Because causes and effects can be so
multiple and complicated, two tests are used to judge whether the causal reasoning is valid.
3. Sign reasoning
• A form of inductive reasoning in which conclusions are drawn about phenomena based on
events that precede or co-exist with (but not cause) a subsequent event.

17. • Signs are like the correlation mentioned above under causal reasoning. If someone argues,
“In the summer more people eat ice cream, and in the summer there is statistically more
crime. Therefore, eating more ice cream causes more crime!” (or “more crime makes people
eat more ice cream.”), that, of course, would be silly. These are two things that happen at the
same time—signs—but they are effects of something else – hot weather. If we see one sign,
we will see the other. Either way, they are signs or perhaps two different things that just
happen to be occurring at the same time, but not causes.
4. Analogical reasoning
• Drawing conclusions about an object or phenomenon based on its similarities to something
else.