1. Correlations
    • are "measures of association"
    • a measurement of linear (straight line) relationship
  2. measure of association
    • a number that measures how related two variables are
    • when two variables are related, this means that when one changes, the other changes
  3. Pearson's product moment correlation
    • the most common correlation
    • referred to as "the correlation"
    • it is used with quantitative (numerical) variables
    • the symbol is r
  4. Linear relationship
    • most common
    • correlation lies between -1 and 1
    • the measure of how close the points in the scatterplot are to the best fitting straight line
    • it's negative when the line goes down, positive when the line goes up, and 0 when the line is flat
  5. regression line
    the best fitting straight line
  6. square of correlation
    • r2
    • sometimes called "variance accounted for" or "shared variance"
    • it is interpreted as the amount of variance in the y variable accounted for by the x variable
  7. residual
    error in the prediction
  8. regression and correlation
    • yeild three important numbers:
    • slope of best fitting line
    • intercept of best fitting line
    • correlation
Card Set
chp 3.2