PHLA10H3 Lecture Notes - Lecture 3: Sample Size Determination, Electrocardiography, Deductive Reasoning
Document Summary
Valid deductive arguments guarantee that the conclusion is true if the premises are true : there is obviously no more info. in the conclusion than was in the premises. Anyone who is 2m tall is more than 1m tall. Although this argument is deductively valid, we have thrown away some of the information available. All deductive arguments are like this ><> its is the cost of the guarantee". We can produce arguments that increase our info. only by giving up the deductive guarantee: ex. The possible gain in information from non-deductive argument is balanced by the risk of error. No guarantee that they are right: ex. Is the inference from a sample of a set of things (people"s opinions, weights, heights: to whole set. Two crucial factors: sample size, sample bias. The more representative" the sample the better: representative vs. random. Probability measures the chance an event will occur: example, sampling, refer to example on ppt.
