1. PROCESS OF ELIMINATION INDUCTIVE REASONING

2. DISCLAIMER Logic is a very complex field of study. Our goal in this unit is just to starting thinking about how we think. Inductive reasoning is not defined as nicely as deductive reasoning and we are only going to look at one way it is used.

3. INDUCTIVE LOGIC A process of reasoning where you start with possible conclusions and then look for evidence that refutes them In other words… Make a guess about what the solutions to a problem might be and then try test them until only one remains.

4. MY SLED DOESN’T START Possible Problems: 1.Kill switch is down. 2.Out of gas. 3.Plugs are fowled 4.Battery is dead 5.Fuel valve is closed Use the process of elimination to determine the problem. Why does this process not guarantee my problem will be solved?

5. WARNING Inductive reasoning (in general) does not lead you to a guaranteed conclusion like deduction does. It can usually only show you that something is very probable. For Example: “All life forms depend on water” Do they?

6. INTRODUCTION TO KNIGHTS AND KNAVES Watch: http://www.youtube.com/watch?v=2dgmgub8mHw We are going to use the Knight and Knave puzzles to practice inductive reasoning. Knights always tell the truth. Knaves always lie.

7. KNIGHTS AND KNAVES PROBLEMS There is a special called “The Island of Knights and Knaves” There are exactly 2 types of inhabitants: -Knights: Who always tell the truth -Knaves: Who always lie. You meet a group of inhabitants and you must figure out each ones type.

8. You meet two inhabitants: Zed and Alice. Zed tells you, `I am a knight or Alice is a knave.' Alice tells you, `Exactly one of us is a knight.' So who is a knight and who is a knave?

9. STEPS 1.Identify the possible cases. 2.Test each case looking for a contradiction. 3.The case without a contradiction is the answer. For full marks you must: Clearly demonstrate all contradictions Clearly explain why there is no contradiction with the correct answer.

10. YOUR ASSIGNMENT There is a Knights and Knaves assignment on the website. I did the first one for you, solve the other puzzles using the same format. Show me when you are done. Practice mine sweeper.