STK4900 - Spring 2009

Exercises in STK4900 -Spring 2009

The lectures and exercise classes in STK4900 will be given Monday-Friday in weeks 12 and 19 (16-20 March and 4-8 May). In these weeks there will be exercises from 13.15 to 16.00. The exercises will consist of two parts: practical exercises (using R on computers) will take place in room C307, while theoretical exercises (using calculator, pen, and paper) will take place in room C317 (except for Wednesdays when they will take place in room C313). Further details on the organisation of the exercises will be provided at the course.

Below is given a plan for the exercises. The plan will be updated as the course progresses.

In the plan "BSS" is short hand for the collection of exercises by B?lviken, Skovlund & Storvik .

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Part 1 (week 12)

Monday 16 March:

Practical exercises:

  • Exercises on t-tests and confidence intervals
  • Exercise 2 page 6 i BSS. In question c you should only compute confidence intervals based on the t-distribution. But you should do so with and without "outlying observations". (R help to the exercise is given here )
  • Exercise 1a-d i the R-exercises . Note that where it is written "Splus" in the R-exercises you should read it as "R". (R help )

Theoretical exercises:

Tuesday 17 March:

Practical exercises:

Theoretical exercises:

Wednesday 18 March:

Practical exercises:

  • Exercise 3.1 page 7 in BSS (R-help )
  • Exercise 3.2 page 8 in BSS (R-help )
  • Exercise 3.3 page 9 in BSS (R-help )
  • Exercise 3 in the R-exercises (R-help ). Questions c and d are optional

Theoretical exercises:

Thursday 19 March:

Practical exercises:

  • Exercise 5 pages 12-13 in BSS (R-help )
  • Exercise 12 pages 22-24 in BSS (R-help ). Before you do this exercise, you have to read into R a function that may compute cross-vallidated R2. It is explained here how you should do this.

Theoretical exercises:

Friday 20 March:

Practical exercise:

  • Exercise 16 page 29 in BSS, except question 5 (R-help )
  • Exercises that remain from previous days.

Theoretical exercises:

Part 2 (week 19)

Monday 4 May:

Practical exercises:

  • Exercise 13 pages 25-26 in BSS (R-help ).
  • Exam ST301 spring 2000: Problem 2 a,b. The output in the exam problem comes from another program than R. You shall do the computations in R and use the output from R when you answer questions a and b in the exam problem (R-help ). Note that the covariate x is the 10-logarithm of the dose given on the data file. (The exam problem is written in Norwegian. Translation will be provided at the exercise classes if needed.)

Theoretical exercises:

Tuesday 5 May:

Practical exercises:

  • Exercise 10.2 page 20 in BSS (R-help )
  • Exercise 14 page 27 in BSS (R-help )

Theoretical exercises:

Wednesday 6 May:

Practical exercises:

  • Exercise 15 page 28 in BSS. In addition to questions 1 and 2 (question 3 corresponsd to 1 and should be omitted), you should also do the following additional questions: 4) Use the log-rank test to test if there is a significant difference between the groups; 5) Fit a Cox regression model with treatment as the only covariate, and interpret the results (R-help )
  • Extra exercise on survival analysis . A description of the data is given here . R-help is given here

Theoretical exercises:

Thursday 7 May:

Practical exercises:

Theoretical exercises:

Friday 8 May:

Practical exercises::

Published Jan. 7, 2009 5:40 PM - Last modified Apr. 29, 2009 10:22 AM
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