Pre-regression Basics. Random Vs. Non-random variables Stochastic Vs. Deterministic Relations Correlation Vs. Causation Regression Vs. Causation Types of Data Types of Variables The Scientific Method Necessary & Sufficient Conditions. Random Vs. Non-random Variables.
It did not rain therefore the football field cannot be wet (How about a sprinkler system?)
The field is wet therefore it must have rained.
(Sprinklers may have been on)
(Contrapositive) The field is dry therefore it did not rain.
(Contrapositive) If past consumption does not influence present consumption then cigarettes are not addictive.