Least squares modelling

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Learning outcomes

  • Understand the difference between correlation and covariance.
  • What the objective function of least squares does
  • Understand and use an analysis of variance table
  • Calculate and interpret the confidence intervals from a least squares model
  • Know about the assumptions required to interpret least squares model coefficients
  • Use the prediction error range from the model
  • Identify outlier points and classify them
  • Use the linear model when there are multiple predictor variables (this is what we are building up towards; we will use this extensively in the next topic)

Extended readings/practice

  • Run the code below to see how to build and use a linear model in R, but see step 16 and onwards in the R tutorial as well.
  • Try some practice problems.
  • Describe a linear regression model you have made for a lab report.
    • What was the \(R^2\) value?
    • How did you calculate the regression model values?
    • Use the same data from your report and instead calculate the standard error, \(S_E\). How do you interpret that \(S_E\) value now?
  • Do the YouTube challenge: find a video on YouTube that explains the central limit theorem, or the confidence interval, or least squares in a way that is different to explained in class (hopefully you find better explanations than mine). Share the link with a friend in your class.
  • Does eating chocolate lead to winning a Nobel prize?

Resources

Tasks to do first Quiz Solution
Watch videos AAA Quiz Solution
Watch videos BBB Quiz Solution
Watch videos CCC Quiz Solution
Watch videos DDD Quiz Solution
Watch videos EEE Quiz Solution