Causal Explanation
Review
• Cau: something which brings about or increas the likelihood of an effect • Correlations point to and give evidence of causal relations, but do not themlves demonstrate causation – Correlation is symmetrical – Causation is directional • Differentiate variables – Independent variable: possible cau, what is manipulated – Dependent variable: possible effect, depends on the independent variable
Review - 2
• Strongest evidence for causation comes from experiments – Manipulate the independent variable and detect effect on the dependent variable – Speak of manipulated independent variable • When manipulation is not possible – Measured independent variable • In either ca, the dependent variable is measured
Review - 3
儿童舞蹈基本功• Testing causing claims – Often requires operationalizing the variable or developing measures in terms of which we can cure data – To confirm a causal hypothesis • Identify a prediction that would not be t
rue if the causal hypothesis were not true –If the prediction is true, reason by modus tollens to the truth of the hypothesis – To falsify a causal hypothesis • Identify a prediction that would be true were the hypothesis true –If the prediction is not true, reason by modus tollens to the falsity of the hypothesis
唯物史观三个基本原理Seeing Caus
• A tradition in philosophy, who roots lie with David Hume, maintains that we never e causation, only events preceding other events • But some visual displays such as tho developed by Albert Michotte are hard to e in any other way
Describe what you e
What is a cau?泥鳅炖豆腐的做法
小正方体• A variable, some of who values bring about or increa the value of the effect variable • Two more specific notions of cau: – The cau is sufficient to bring about the effect – The cau is necessary to bring about the effect • Neither works perfectly, but each is suggestive of important features of causation and help us understand how to test causal claims
• Conditional relations between statements captured with the connnective “if, then” – If the score is tied, then we will play another round • The score being tied is sufficient for playing another round • Playing another round is necessary when the score is tied – Better captured by • Only if we played another round was the score tied • We can extend the notions of necessary and sufficient to caus
Recall the Logic of Necessary and Sufficient Conditions
Sufficient causchange什么意思
• Examples of factors sufficient to bring about an effect – Dead battery is sufficient for car not starting – Placing water in a normally operating freezer is sufficient for it freezing – Ingesting (enough) hemlock is sufficient for dying – Incread exerci without eating more is sufficient for weight loss.
The value of sufficient caus
• A sufficient cau gives us a recipe for producing an effect we want – If you don’t want someone to drive your car, totally run down the battery – If you want to loo weight, exerci
• “Whenever I get the urge to exerci, I lie down until the feeling pass away.”
Robert M. Hutchins, former President of the University of Chicago
• I have never taken any exerci, except for sleeping and resting, and I never intend to take any. Exerci is loathsome. – Mark Twain, Essays: Seventieth Birthday
什么操场
• For many conditions in which you think you have found a sufficient cau, an exception can be found – If you take an antidote with your hemlock (should one be found), you might escape death – If you put salt in the water, it may not freeze even when temperature is less than 32o F
The difficulty with sufficient caus
• Few factors we identify as caus are really sufficient to bring about their effect – They suffice only in the context of background conditions that are assumed to be in place Turning the ignition switch will start the car only if it is hooked up to the rest of the ignition system, there is an engine in the car, there is gas, oxygen is available, . . . Often need to specify a conjunction of factors to arrive at a sufficient cau • and it is very difficult to note all of them
The difficulty with sufficient caus
Necessary caus
• Something that is necessary to produce an effect: – Sex is necessary for producing babies – Oxyg
en is necessary for combustion – Herpes zoster is a necessary cau of chickenpox – Early exposure to language is necessary for normal language development
For want of . . .深圳过年哪里好玩
• • • • • • For want of a nail, the shoe was lost, For want of the shoe, the hor was lost, For want of the hor, the rider was lost, For want of the rider, the battle was lost, For want of the battle, the kingdom was lost, And all for the want of a horshoe nail!
金吒木吒哪吒
The value of necessary caus
• Provide a way of preventing something – Avoiding x does prevent babies (and AIDs) – Eliminating oxygen does stop fires – Not having Herpes zoster in you prevents chickenbox
