1. Inductive Reasoning

2. Essential Questions
How can new knowledge be acquired using inductive logic?
What is more certain, the conclusions drawn from deductive or inductive reasoning?
What are some of the issues with depending on inductive reasoning as a way of knowing?

3. Comparing Inductive vs. Deductive Reasoning
Inductive reasoning starts from a specific set of observations and leads to a general conclusion.
Deductive reasoning starts from a general statement/premise and leads to a specific conclusion.

4. Thinking …
Since inductive reasoning moves from the observed to the unobserved it enables us to make everyday generalizations or inferences about things we observe.
For example: since my neighbors dog is always friendly to me when I walk past it I am confident that it will not bite me today.
Can you think of any everyday examples of inductive reasoning you have used recently?
You notice that the pavement is wet when you walk to the bus in the morning. Therefore you infer that it rained during the night.
You know you left your mobile phone in either your coat pocket or in your bag. It is not in your coat pocket therefore it must be in your bag.
Every time I boil water its boiling point is 100oC. Therefore water boils at 100oC

5. Use of Inductive Reasoning in Marketing and Statistics
Statistics makes general statements about a general population using data collected from a random sample.
Used in many fields: drug development, medical research, insurance, economics, psychology, engineering, environmental science, engineering. . .
Correlations are drawn between the observations made and the possible factors that contribute to their occurrence or cause.

6. Issues with Inductive Reasoning:
We cannot totally rely on what we observe with our senses.
How many examples do you need to observe before a general conclusion can be drawn?
Statistics that use inductive reasoning can be misused, distorted, and misinterpreted especially if they make generalizations beyond what the data allows.
Inductive reasoning produces only general statements so you can never guarantee the truth of the conclusions made.
Generalizations …
Sense, which is provided by the world Perception which is provided by our minds
The way we see something depends partly on the context in which we see it
2. Our mind misinterprets what we sense – optical illusions
3. We have a natural tendency to look for meaning in what we see.
4. Our EXPECTATIONS influence how we see things
5. As humans we are limited by the range of frequencies we can hear and see.
6. Different cultures respond to smells and taste differently.
7. How we sense world is affected by our emotional state.
8. Our sense perception is influenced by age, practice. For example we need to learn where things are, how to pour liquids etc.
9. Memories - If we taste or smell something that makes us sick we remember it and it makes it hard when we meet this again. It brings back bad memories.
10. Our brain can only see one thing at a time, so it has to be selective in what it sees at any moment. This means our observations can be unreliable, because we don’t see everything in front of us?

7. What distinguishes a good generalization?
You should look at a reasonable number of instances. If you see one dog swimming, this is not enough to conclude that all dogs can swim.
You should look at a variety of circumstances. Look at a variety of different breeds of dogs swimming.
You should actively look for counter examples. Ask if anyone has seen a dog that can’t swim.
You should demand more evidence (coherence) to support surprising claims.
You should be aware of the subject area and keep in mind that generalizations in the natural sciences are more reliable than those in the social sciences.

8. Lateral Thinking – Creative Reasoning
Since we cannot not rely entirely on inductive or deductive reasoning as a way of knowing there are times we need to be able to think in a way that does not involve traditional forms of deductive and inductive logic.
We need to be able to think outside the box and come up with more creative ways of drawing conclusions. This is called lateral thinking.
Lateral thinking alerts us to things we assume without realizing we have assumed them.
Which do you think is easier: having the courage of your convictions, or having the courage to question your convictions?

9. Activity: Give a rational explanation to each of the following
situations. In each case you need to question your
assumptions and try and think outside the box.
A man walks into a bar and asks the barman for a glass of water. The barman pulls out a gun and points it at the man. The man says thank you and walks out.
A women is lying dead in a field. Next to her is an unopened package. There is no other creature in the field. How did she die?
The man has hiccups.
The women's parachute failed to open
Plant three equidistant from one another in an equilateral triangle. Then build a mound of the right height in the middle of the triangle and plant the fourth tree on top of it.

10. Comparing Deduction and Induction

11. Bibliography
Theory of Knowledge Course Companion, Dombrowski, Rotenberg and Bick, OUP
Theory of Knowledge for the IB Diploma, van de Lagemaat, Cambridge
Theory of Knowledge, Alchin, Hodder Murray