a. Focusing mainly on the idea of survey-based comparison. If Obama is beating Romney in the polls on the edge of MoE, what can we say? What can we not say? b. Show how this applies longitudinally as well – if Obama’s approval rating increases, but the increases is within MoE, what can we say? [...]
Chapter Six
Cut-points and Specificity vs. Sensitivity
a. A cut-point is any point on a continuous scale we use to define a separation between states or conditions. b. Examples: High blood pressure, Failing grades, Psychological conditions based on tests, Recessions. c. Cut-points aren’t arbitrary (usually). But they always involve some non-numerical judgment on what is important. d. In the context of comparison, [...]
Percent vs. Percentiles
a. Pretty standard – getting students to understand what the difference is between these, and when to use each. b. Example: On the retest I jumped from the 40th percentile to the 90th. What does that mean? What does that not mean?
The Black Art of Choosing Your Denominator
a. Example: The rich pay a larger percentage of tax revenue than anyone else vs. The rich pay a larger percentage of their income than anyone else. b. Dueling percentage redux:
Net vs. List, Effective vs. Statutory Cost
When we are measuring the price of anything, it’s tempting to measure “list” price — that is, what the asking price of a thing is. In many cases that’s fine — the asking price for a two liter of Diet Coke is most likely the same as the selling price. So if we average what [...]