"There are three kinds of lies: lies, damned lies, and statistics." -
Charles Wentworth Dilke (1843–1911).
Math 263 Fall 2011
Introduction to Statistics and Biostatistics
Announcements
-
Review Session for the Final Exam:
- Location: Math 501
- Date: Tuesday, December 13, 2011
- Time: from 5pm to 6:30pm.
- Here is a new final info. It has a link to Chapter 9 and 12 practice problems.
- Rules of newly announced extra credit are here.
- An updated list of R resources is at the bottom of the page, including tutorials and refcards ("cheat sheets").
-
You will find Chapter 9 materials here. There is a PDF file showing step-by-step how to conduct a chi-square test. Also, there are R examples (in the R subfolder) which contain real scripts I used to solve some of the Chapter 9 WebAssign problems. You will also find the output I generated today by running R in class. If you use Excel for solving Chapter 9 WebAssign homework, you can still benefit by using the outer product operator (%o%) which you can call from R commander after you move some data to R.
You may use "Put R variable" this time to transfer data to R; if you transfer data using "Put R data frame", make sure to include table headings in the transfer, so that data have names, say "x" and "y". If the frame is called "aframe", you can access individual columns by using variable names "aframe$x", "aframe$y". Alternatively, you can use
attach(frame)
after which R makes the variables named "x" and "y", which stand for the columns of the data frame. - Excel/R Assignment 6 is now available here.
- Excel/R (this time pure R!) Assignment 5 is now available here.
- There is a big practice test (over 50 problems) for Midterm 3 and the Final Exam. The answers to the practice test WILL NOT be posted.
Links to general resources
- Syllabus, including course policies
- Calendar
- WebAssign
- PowerPoint Lecture Notes: 6e | 7e
- Student Resource CD
- Another Math 263 site
- Rules of grading multiple choice questions
Clicker Quiz Results
Excel Assignments
Please turn in Excel assignments as hard copy, with every sheet bearing
your name, before class on the due day.
Assignment 1 - due September 7
Assignment 2 - due September 21
Assignment 2.5 - due September 26
Please refer to Assignment #2 for the dataset.
- Instructions (Word 2007, with embedded Excel example)
- Instructions
(Word 2003, only text, no embedded Excel due to incompatibility)
- Instructions (PDF, no "live" excel objects)
- Original instructions
and an Excel example at another website.
Assignment 3 - due October 24
Please refer to Assignment #2 for the dataset.
Assignment 4 - due November 14
Two last assignments below are extra credit.
You may turn it in to the Math Office (Math 108) if you do it after
December 5 and not during my office hours.
Assignment 5 - due December 9
Assignment 6 - due December 9
Data sources
Video Tutorials I recorded (for Windows Media Player)
Links following the material discussed in class
- The definitive guide on how to calculate the five-number summary by hand
- How to make a five-number summary with R?
- A detailed definition of a Quartile
- There is not a single way to find quartiles! See this insightful discussion
- Interquartile range (IQR)
-
Wikipedia's
skewness of distribution article. Note:
left-skew (right-skew) means left tail is longer than the left
(right). Also left-skew = negative skew and right-skew = positive
skew, using another terminology.
-
Download R from here
-
Download RExcel from here
- RExcel Video
- RExcel Wikipedia page
-
A local copy of RAndFriendsSetup.exe. May be outdated!
Use only if you cannot obtain a copy from the distribution server in Austria. Disclaimer:
I do not take any responsibility for the functioning of this third-party file,
or the possibility that it may contain malware.
-
A third party installation instructions.
Disclaimer: I do not know if these work, and I do not take responsibility for their content,
or possible malware on this website.
- Midterm 1 Information - now updated for Fall 2011
- PDF files explaining how to do linear regression with R
- A page explaining how to do
linear regression with Excel
- Local SimpleR resources
- Wikipedia article on the sum of squares and coefficient of determination
- Class notes on regression and sum of squares
- 2011 lecture notes example (by hand)
- Exact linear relationship example (PDF)
-
Non-Exact linear relationship example. Contains an R
regression calculation example, and a full calculation of the sums
of squares (PDF).
Chapter 3 Links
- Experimental Unit discussion
- Statistical unit definition on Wikipedia
Midterm 2
Chapter 6
Notes related to Chapter 6 are here:
Chapter 7
Notes related to Chapter 7 are here:
Midterm 3
- Midterm 3 Information - updated for Fall 2011
Chapter 7 - the two-sample t-test
-
Wikipedia article
on the Welch's test with the Welch-Satterthwaite formula for the number
of degrees of freedom. Note that this is the test described in the
book and implemented by the R function t.test,
for the situation when sample sizes are uneven and
we have no reason to believe that the two populations
have identical variances.
-
An excellent Wikipedia summary of several variants of the t-test
used for a number of distinct situations (such as two-sample test when the variances
of both populations are believed to be the same).
-
A two-sample t-test in R for the example presented in class:
-
An R example
Chapter 9 - the chi-square test and two-way tables
-
An R example
-
A PDF with a chi-squared test.
-
Another site
illustrating using R for chi-squared test for two-way tables. The
example uses a file with heart attack data which can be found here (please note that you will
find there a number of other useful R examples). The particular
file that needs to be read is Here is a local mirror of this site.
-
An example
of how to run the scripts and read data with R.
Chapter 12 - one-way ANOVA
-
R examples
-
A nice example of
one-way ANOVA
with boxplots and linear model fitting. Also, illustrates
working with lists ('sapply') and splitting data by levels
of a factor ('split').
-
An R example of
one-way ANOVA
with pairwise t-test (no data appears to be available, just the
sequence of R commands).
-
A very cojent explanation of
2-way ANOVA.
More R resources
- A list of R tutorials.
- A list of R cheatsheets, especially
this one.
- http://www.statmethods.net/ - a reference for many commonly used methods.
-
http://www.oga-lab.net/RGM2/images.php?show=all&pageID=2007
- a rich review of R graphical capabilities.
The final
- The Final Information - partially updated for Fall 2011
Excel Assignments
Please turn in Excel assignments as hard copy, with every sheet bearing
your name, before class on the due day.
Assignment 1 - due September 7
Assignment 2 - due September 21
Assignment 2.5 - due September 26
Please refer to Assignment #2 for the dataset.- Instructions (Word 2007, with embedded Excel example)
- Instructions (Word 2003, only text, no embedded Excel due to incompatibility)
- Instructions (PDF, no "live" excel objects)
- Original instructions and an Excel example at another website.
Assignment 3 - due October 24
Please refer to Assignment #2 for the dataset.Assignment 4 - due November 14
Two last assignments below are extra credit.
You may turn it in to the Math Office (Math 108) if you do it after
December 5 and not during my office hours.
Assignment 5 - due December 9
Assignment 6 - due December 9
Data sources
Video Tutorials I recorded (for Windows Media Player)
Links following the material discussed in class
- The definitive guide on how to calculate the five-number summary by hand
- How to make a five-number summary with R?
- A detailed definition of a Quartile
- There is not a single way to find quartiles! See this insightful discussion
- Interquartile range (IQR)
-
Wikipedia's
skewness of distribution article. Note:
left-skew (right-skew) means left tail is longer than the left
(right). Also left-skew = negative skew and right-skew = positive
skew, using another terminology.
- Download R from here
-
Download RExcel from here
- RExcel Video
- RExcel Wikipedia page
- A local copy of RAndFriendsSetup.exe. May be outdated! Use only if you cannot obtain a copy from the distribution server in Austria. Disclaimer: I do not take any responsibility for the functioning of this third-party file, or the possibility that it may contain malware.
- A third party installation instructions. Disclaimer: I do not know if these work, and I do not take responsibility for their content, or possible malware on this website.
- Midterm 1 Information - now updated for Fall 2011
- PDF files explaining how to do linear regression with R
- A page explaining how to do linear regression with Excel
- Local SimpleR resources
- Wikipedia article on the sum of squares and coefficient of determination
- Class notes on regression and sum of squares
- 2011 lecture notes example (by hand)
- Exact linear relationship example (PDF)
- Non-Exact linear relationship example. Contains an R regression calculation example, and a full calculation of the sums of squares (PDF).
Chapter 3 Links
- Experimental Unit discussion
- Statistical unit definition on Wikipedia
Midterm 2
Chapter 6
Notes related to Chapter 6 are here:Chapter 7
Notes related to Chapter 7 are here:Midterm 3
- Midterm 3 Information - updated for Fall 2011
Chapter 7 - the two-sample t-test
- Wikipedia article on the Welch's test with the Welch-Satterthwaite formula for the number of degrees of freedom. Note that this is the test described in the book and implemented by the R function t.test, for the situation when sample sizes are uneven and we have no reason to believe that the two populations have identical variances.
- An excellent Wikipedia summary of several variants of the t-test used for a number of distinct situations (such as two-sample test when the variances of both populations are believed to be the same).
- A two-sample t-test in R for the example presented in class:
- An R example
Chapter 9 - the chi-square test and two-way tables
- An R example
- A PDF with a chi-squared test.
- Another site illustrating using R for chi-squared test for two-way tables. The example uses a file with heart attack data which can be found here (please note that you will find there a number of other useful R examples). The particular file that needs to be read is Here is a local mirror of this site.
- An example of how to run the scripts and read data with R.
Chapter 12 - one-way ANOVA
- R examples
- A nice example of one-way ANOVA with boxplots and linear model fitting. Also, illustrates working with lists ('sapply') and splitting data by levels of a factor ('split').
- An R example of one-way ANOVA with pairwise t-test (no data appears to be available, just the sequence of R commands).
- A very cojent explanation of 2-way ANOVA.
More R resources
- A list of R tutorials.
- A list of R cheatsheets, especially this one.
- http://www.statmethods.net/ - a reference for many commonly used methods.
- http://www.oga-lab.net/RGM2/images.php?show=all&pageID=2007 - a rich review of R graphical capabilities.
The final
- The Final Information - partially updated for Fall 2011