7 Day 7 (June 17)

7.1 Announcements

• Assignment 1 is graded. Email a revised assignment if you don’t like your grade.

• Remember to upload picture of extra credit signature page from Friday to canvas

• Assignment 2 is due Wednesday

• Recommended reading

  • Chapters 2 and 3 (pgs 13 - 46) in Linear Models with R

• Selected questions from journals

  • “I was confused about the Nelder-Mead method in the coding in R, especially when reading the code and trying to manipulate it.”
  • “I think I did not follow the difference between the square loss and absolute loss. There is a simple mathematical difference between both, and you obtain different lines from these two methods. However, I have some questions behind these two methods. First, which one are more efficient in terms of errors? How about the applicability of these two methods in terms of computing (such R for example)? And finally, these two ways of “calculate” the loss are part of the least squares function?

7.2 Estimation

• Three options to estimate \(\boldsymbol{\beta}\)
  • Minimize a loss function
  • Maximize a likelihood function
  • Find the posterior distribution
  • Each option requires different assumptions
• Live example
  • Research publication
  • Data
  • R Script