Difference between revisions of "Least squares modelling"

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* Run the code below to see how to build and use a linear model in R, but see [[Software_tutorial | step 16 and onwards]] in the R tutorial as well.
* Run the code below to see how to build and use a linear model in R, but see [[Software_tutorial | step 16 and onwards]] in the R tutorial as well.
* Try some [[Practice_questions|practice problems]].
* Try some [[Practice_questions|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.
* [http://www.nejm.org/doi/full/10.1056/NEJMon1211064 Does eating chocolate lead to winning a Nobel prize]?
* [http://www.nejm.org/doi/full/10.1056/NEJMon1211064 Does eating chocolate lead to winning a Nobel prize]?
== Resources ==
<!--
* [[Image:Nuvola_mimetypes_pdf.png|20px|link=Media:2015-4C3-6C3-Least-squares-modelling.pdf]]  [[Media:2015-4C3-6C3-Least-squares-modelling.pdf| Class notes 2015]]
* [[Image:Nuvola_mimetypes_pdf.png|20px|link=Media:2014-4C3-6C3-Least-squares-modelling.pdf]] [[Media:2014-4C3-6C3-Least-squares-modelling.pdf | Class notes 2014]]
* [http://learnche.org/pid/least-squares-modelling/index Textbook, chapter 4]
* Quizzes (with solutions): attempt these after you have watched the videos
:{| class="wikitable"
|-
! Tasks to do first
! Quiz
! Solution
|-
| Complete steps 10, 11, 12 and 13 of the [http://learnche.mcmaster.ca/4C3/Software_tutorial software tutorial] 
(also steps 1 through 9)
| [ Quiz]
| [ Solution]
|-
| Watch videos 1, 2, 3,  4, and 5
| [https://docs.google.com/document/d/19NnM1v7yut1q0HFaHMQmNg6zMH2UPN1rrHZl7l38qBI  Quiz]
| [https://docs.google.com/document/d/1YcF4PxxfQqnz4UqgGZMWv3zfFmmjB7uSkNfQ9XMe97A Solution]
|-
| Watch videos 6, 7, and 8
| [https://docs.google.com/document/d/1BySja0o1O8MtZOitV42BU2bnjWmzH_vARcXCbh5OviI Quiz]
| [https://docs.google.com/document/d/17jKKHwgVLkBT04R3OgUr9TqSzCGkxVYBP-fZtuiszig Solution]
|-
| Watch videos 9 and 10
| [https://docs.google.com/document/d/1qMBqum4kdgLBK3dlzXncZJm42NKdp8pnsp9jxG_dKXA Quiz]
| [https://docs.google.com/document/d/19mCY3qCpVKLzvOBpa-c1t7JDzLTl0xagnivRpslnTD0 Solution]
|-
| Watch videos 11, 12, and 13
| [https://docs.google.com/document/d/1zxOUn30wTeg8xiJfIgfZ3WKgiUk3hqrnCV-sDTrlFiA Quiz]
| [https://docs.google.com/document/d/19RozNWVpmQo5oJOfw2SDhWZrJ2Sbpq2LuWFq8NsLN6g Solution]
|-
| Watch videos 14, 15, and 16
| [https://docs.google.com/document/d/1ZJ1aZ-hvS11-k5btkBqb1X16RAihbFTDjX-fNX8iQm8 Quiz]
| [https://docs.google.com/document/d/10h2qavaw08AYC5qGAWyemXrgro0F-ARBaDnoE52S77Y Solution]
|}
-->

Revision as of 15:31, 3 January 2016

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