Chapter 6: Bivariate Data Analysis Notes

Sections

1. 6A Scatterplots and describing association Mastered

   Bivariate data, explanatory and response variables, drawing a scatterplot, and describing an association by its direction, form and strength, including outliers.

   Open notes
2. 6B Pearson's correlation coefficient Mastered

   What Pearson's correlation coefficient r measures, the scale from -1 to 1, classifying strength, finding r with a calculator, and what r cannot tell you.

   Open notes
3. 6C Correlation and causation Mastered

   Why a strong correlation does not prove that one variable causes the other: lurking variables, coincidence, reverse direction, and how to word conclusions about association.

   Open notes
4. 6D The least-squares line of best fit Mastered

   Fitting the least-squares regression line with a calculator or from summary statistics, interpreting its gradient and intercept in context, and understanding residuals.

   Open notes
5. 6E Interpolation, extrapolation and investigations Mastered

   Making predictions from a least-squares line, the difference between interpolation and extrapolation, judging reliability, and planning a bivariate statistical investigation.

   Open notes