Causal Reasoning

Causal Reasoning By: Ellyn Polley

Explanation • One causes the other • Useful to establish claims of policy • Event A is necessary for event B to occur • Ex.- The Dog hit the table. The vase fell off the table.

Cause and Effect vs. Correlation • Cause and Effect • One thing causes another • Correlation • Two events seem to occur together or to be otherwise associated • Ex.- washing your car, then it rains

Test for Causal Reasoning • Must distinguish between cause and effect • Ex. Is and obnoxious person that way because he or she is ignored or is this person ignored because he or she is obnoxious? • Must show that the cause is sufficient to produce the effect • Ex. The crime rate went down six months before hiring a new police chief. Questions that need to be answered before causality is shown: Can a claim that credits the chief for the lower crime rate be made?

Test for Causal Reasoning 2. Must show that the cause is sufficient to produce the effect • Ex. The crime rate went down six months before hiring a new police chief. • Questions that need to be answered before causality is shown: • Can a claim that credits the chief for the lower crime rate be made? • Do the policies implemented by the new chief directly affect the rate? • Did previous programs in place before the chief was hired have any effect?

Test for Causal Reasoning • Alternative Causes • Other causes may produce the same effect • Must rule out other causes • Ex. Improved grades could be a result of better study habits, better teachers, or better learning resources

John Stuart Mill • British Philosopher (1806-1873) • Devised five methods to analyze causal relationships • Method of Agreement • Method of Difference • Joint Method of Agreement and Difference • Method of Concomitant Variation • Method of Residues

Example • An unusual amount of students suffered from nausea in one afternoon. The nurse suspects it is a result of something the students had for lunch. She needs to support the conclusion that Eating _____ causes nausea. • She uses Mill’s Method to help

Method of Agreement • What did they have for lunch? • Student 1 ate pizza, coleslaw, soda and a cookie • Student 2 ate a hot dog, French fries, coleslaw and tea • Student 3 ate pizza, coleslaw, and tea • Student 4 ate fries and coleslaw • The nurse concluded that coleslaw caused the nausea

Method of Difference • Two students went to the nurse, one was nauseous the other was not. • The students had the same lunch but the nauseous one had coleslaw and the other did not. • The nurse can conclude that the coleslaw causes nausea because it appeared in one case but not the other.

Joint Method of Agreement and Difference • Two groups came to the nurse, one suffered nausea and ate coleslaw the other group felt fine and did not eat coleslaw. • The nurse arrives at the same conclusion

Method of concomitant variation • Student 1 ate no coleslaw and feels fine • Student 2 ate one bite of coleslaw and feels a little queasy • Student 3 ate coleslaw and is ill • Student 4 ate a two servings and is hospitalized

Method of Residues • The nurse already knows that pizza causes a headache and the tea causes a rash • A student comes in saying they are suffering from a headache, nausea, and a rash. They ate pizza, tea, and coleslaw for lunch • They can conclude that the additional effect of nausea is caused by the additional circumstance of coleslaw

Questions • A _____ is when two events seem to occur together. • T/F – If event A occurs, then event B must occur. • ____ and ____ is when one event causes the other event to happen

Answers • Correlation • False • Cause and Effect

Causal Reasoning