The Language of Statistical Decision Making Lecture 1 Section 1.3 Fri, Sep 1, 2006
I Don’t Feel Your Pain! Study: Men Enjoy Watching Bad Guys Suffer
Man or Woman? Suppose we are not told a subject’s sex, but we are told that the subject felt empathy for the cheater. Would we guess that the subject is a man or a woman? Why? Would we necessarily be correct?
Populations and Samples Statistical inference
Samples and Inferences Population
Samples and Inferences Population Take Sample Sample
Samples and Inferences Population Take Sample Make Observations Sample Data
Samples and Inferences Population Inference Draw an Inference Take Sample Make Observations Sample Data
Samples and Inferences Population Inference Draw an Inference Take Sample Make Observations Sample Data
Hypotheses Hypothesis A hypothesis is often a statement that is proposed to explain something that is known to be true.
Hypotheses The Null Hypothesis – The conventional belief about the population, or the status quo, or the neutral position. It receives the benefit of the doubt. The Alternative (Research) Hypothesis – An alternative to the null hypothesis. It bears the burden of proof. Typically, the researchers are trying to prove the alternative hypothesis.
Hypothesis Testing Population
Hypothesis Testing Null Hypothesis Population
Hypothesis Testing Null Hypothesis Population Alternative Hypothesis
Hypothesis Testing Null Hypothesis Population Alternative Hypothesis Sample
Hypothesis Testing Null Hypothesis Population Alternative Hypothesis Sample Evidence
Hypothesis Testing Null Hypothesis Population Alternative Hypothesis Which Hypothesis Is Supported? Sample Evidence
Hypothesis Testing Null Hypothesis Population The evidence may support the Null Hypothesis… Sample Evidence
Hypothesis Testing Null Hypothesis Population …if any discrepancy can be attributed to chance Sample Evidence
Hypothesis Testing Population Alternative Hypothesis The evidence will support the Alternative Hypothesis… Sample Evidence
Hypothesis Testing Population Alternative Hypothesis …if the discrepancy cannot be attributed to chance Sample Evidence
Statistical Significance The data are called statistically significant if their deviation from what would be expected under the null hypothesis is too great to be attributed to chance. Example: The incidence of cancer in one community is 8% and in another community it is 10%. Can the difference be attributed to chance?