1. Tests handed back last 15min of class + review of trouble sections.
2. Take-Home Midterm Assigned TODAY. DUE Wed. 12th at Midnight. Form groups of 3 or 4.
3. Blog and Podcast Reviews: The clock is ticking!
Warm Up
Conditional Reasoning Part 1
Intro: Bonus Question, The Perfect Vending Machine, Affirming the Consequent
Example 1
Version 1
(P1) If I put money in the vending machine then I get a can of coke.
(P2) I put money in the vending machine.
(C) ?
Version 2
(P1) If I put money in the vending machine then I get a can of coke.
(P2) I've got a can of coke.
(C) ?
Example 2
Version 1
(P1) If it's raining then there are clouds.
(P2) It's raining.
(C) ?
Version 2
(P1) If it's raining then there are clouds.
(P2) There are clouds.
(C) ?
Example 3
Version 1
(P1) If we booga booga then we oompalumpa.
(P2) We oompalumpa'ed.
(C) ?
Version 2
(P1) If we booga booga then we oompalumpa.
(P2) We booga booga'ed.
(C) ?
Example 4
Version 1
(P1) If Maru is a cat then Maru is a reptile.
(P2) Maru is a cat.
(C) ?
Version 2
(P1) If Maru is a cat then Maru is a mammal.
(P2) Maru is a mammal.
(C) ?
Example 5
(P1) If he liked it then he should have put a ring on it.
(P2) Whoa oh oh, oh oh oh;
(P3) Whoa oh oh, oh oh oh;
(P4) He should have put a ring on it.
(C) ?
Explanation:
Conditional reasoning uses If/then statements. The "if" clause is called the "antecedent" and the "then" clause" is called the "consequent." A common short-hand method for writing if-then statements is to take the first letter or letters of a key term in the antecedent, draw an arrow, then write the first letter of letters of the key terms in the consequent.
Example:
If I'm late for work then I'll get in trouble = L --> T. (The 'L' is for 'late' and the 'T' is for 'trouble'.)
The valid form of conditional reasoning is called modus ponens. One premise is the full conditional statement, the other premise is the antecedent (the order doesn't matter), and the conclusion is the consequent. One incorrect form of conditional reasoning is called "affirming the consequent". Affirming the consequent is when the consequent is a premise and the antecedent is the conclusion.
Example of modus ponens (always valid):
(P1) If I'm late for work then I'll be in trouble.
(P2) I'm late for work.
(C) I'm going to be in trouble.
(P1) If X then Y.
(P2) X.
(C) Y.
Example of affirming the consequent (never valid)
(P1) If I'm late for work then I'll be in trouble.
(P2) I'm in trouble.
(C) I was late for work.
(P1) If X then Y.
(P2) Y.
(C) X.
Conditional Reasoning Part 2. Denying the Antecedent and Modus Tollens
Example 1
Version 1
(P1) If the Ukraine asserts its independence from Russia then Russia will attack it.
(P2) The Ukraine didn't assert its independence from Russia.
(C) Russia won't attack it.
Version 2
(P1) If the Ukraine asserts its independence from Russia then Russia will attack it.
(P2) Russia didn't attack the Ukraine.
(C) ?
Example 2
Version 1
(P1) If you work hard then you will be wealthy.
(P2) You didn't work hard.
(C) ?
Version 2
(P1) If you work hard then you will be wealthy.
(P2) You aren't wealthy.
(C) ?
Example 3
Version 1
(P1) If the bubba had wheels she would have been a street car.
(P2) The bubba doesn't have wheels.
(C) ?
Version 2
(P1) If the bubba had wheels she would have been a street car.
(P2) The bubba isn't a street car.
(C) ?
Example 4
Version 1
(P1) If you do the hokey pokey then you'll turn yourself around.
(P2) I didn't do the hokey pokey.
(C) ?
(P1) If you do the hokey pokey then you'll turn yourself around.
(P2) I didn't turn myself around.
(C) ?
Try for examples 1-5 Part 1
Explanation:
Just as there is a valid and invalid version of positive formulations of conditional reasoning there is a valid and invalid version of negative formulations of conditional reasonings. The valid formulation is called modus tollens: One premise is the conditional the other premise is the negation of the consequent. The invalid formulation is when one premise is the conditional and the other premise is the negation of the antecedent.
Example of Modus Tollens (Always Valid)
(P1) If I eat too much then I feel bloated.
(P2) I don't feel bloated.
(C) I didn't eat too much.
(P1) If X then Y.
(P2) Not Y.
(C) Not X.
Example of Denying the Antecedent (Never valid)
(P1) If I eat too much then I feel bloated.
(P2) I didn't eat too much.
(C) I don't feel bloated.
(P1) If X then Y.
(P2) Not X.
(C) Not Y.
Conditional Reasoning Part 3: Combining Concepts: Conditional Reasoning + Hidden Assumptions
Example 1:
The ingredients of this food are all natural. It's good for your health.
Example 2:
Universal health care is a bad idea because it's socialist.
Example 3:
Bob is a nice guy: he gave me a free frozen yogurt!
Example 4:
I'm going to see the new super-hero movie. It's going to be great!
Example 5:
I just started taking cryo-magnum super pump muscle blaster pre-workout. I'm gonna be swole in a month.
Conditional Reasoning Part 4: Combining Concepts: Conditional Reasoning and Falsificationism
A. Hypothesis/Claim: Echinacea cures the common cold.
Conditional Hypothesis: If I take echinacea then my cold will be cured.
Construct the Argument: How does this relate to falsificationism? How would we employ it?
B. Hypothesis/Claim: Thimerisol in MMR vaccines causes autism.
Conditional Hypothesis?
Construct the Argument. Employ falsificationism and suggest how you'd test the hypothesis.
C. Hypothesis/Claim: Sour sop cures cancer.
Conditional Hypothesis?
Construct the Argument. Employ falsificationism and suggest how you'd test the hypothesis.
D. Hypothesis/Claim: Eating/drinking supplement X prevents me from getting sick.
Conditional Hypothesis?
Construct the argument. Employ falsificationism and suggest how you'd test the hypothesis.
E. Hypothesis/Claim: Weight-loss supplement "Super Quantum Lipo-Fat Burner Extra Mega Shred" causes weight loss.
Conditional Hypothesis?
Construct the argument. Employ falsificationism and suggest how you'd test the hypothesis.
Key Concepts:
A) What the natural prevalence rate?
B) Control Group.
Take Home Midterm:
1. Form groups of 3 or 4.
2. Due Wed 12th at midnight.
Test:
1. Your grade on this test is a good predictor of your grade in the course unless you change what you're doing.
2. I'm available for extra help after class and/or by appointment.
Homework 7A:
1. Complete the examples of Part 3 that we didn't do in class. 1. Complete the argument by stating the missing premise in conditional form (If...then...). 2. Rewrite the argument as modus tollens, denying the antecedent, and affirming the consequent.
2. Complete Part 4.
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