Kathy Welch Homepage
Kathy Welch's Homepage.
Address:
CSCAR
The University of Michigan,
3554 Rackham Building
915 E. Washington St.
Ann Arbor, MI 48109-1070

I work at CSCAR, the Center for Statistical Consultation and Research at the University of Michigan. We are located on the third floor of the Rackham Building on the University of Michigan Central Campus, (Rackham is located at J-1, if you click on this link to a map of Central Campus) near the Carillon.

Check out our book!

Linear Mixed Models: A Practical Guide using Statistical 
Software

I am co-author of a book published by Chapman & Hall/CRC Press in November, 2006, Linear Mixed Models: A Practical Guide using Statistical Software with Brady West from CSCAR and Andrzej Galecki from the Institute of Gerontology at the University of Michigan. This book describes how to carry out an analysis of clustered, longitudinal, or repeated measures data sets using linear mixed modeling (LMM) procedures in SAS, SPSS, Stata, R, and HLM. The data sets analyzed in the book were mostly from clients with whom we have consulted at CSCAR, and show how real-world problems can be approached with widely used software. We provide descriptive statistics and basic graphics for each data set, model-building strategies, and step-by-step information on how to analyze each data set with each software procedure, including the appropriate syntax, and a comparison of the models fitted using each procedure. We also provide an overview of the theoretical concepts involved in LMMs. You can check the LMM book web page for data sets and up-to-date syntax for each of the software packages.

My home page has resources for the workshops and courses that I either teach, co-teach or assist in teaching, and some graphics on how to import an Excel Spreadsheet into SAS. There are also some fun pictures at the end of this page.

A web page listing some of my professional qualifications is available, if you Click here.

Phone: (734) 764-7828
Fax: (734) 647-2440
email: kwelch@umich.edu

Epidemiology 759: Introduction to SAS

I teach a week-long course on Introduction to SAS, Epidemiology 759, in the Graduate Summer Session in Epidemiology, at the University of Michigan School of Public Health.

Zipped and other data files can be downloaded here:

  • epid759.zip Zipped archive containing SAS command files, Excel files, SPSS portable files, etc. Download to desktop and then double-click to extract data from the archive.
  • sasdata1.zip SAS version 6 data sets
  • sasdata2.zip SAS version 8/9 data sets (.sas7bdat) and SAS xport data sets (.xpt)
  • bmi1.xls Excel file for Tecumseh Study Round I
  • bmi2.xls Excel file for Tecumseh Study Round II
  • bmi3.xls Excel file for Tecumseh Study Round III
  • General handouts can be found here:

  • Preparing Data Using Excel This web page from CSCAR gives an explanation of how to set up an Excel file for use with a statistical package, such as SAS or SPSS.
  • fonts.sas This little SAS command file contains a line of code that will make your SAS output look good when printed from any computer (it will get rid of the funky-looking little row, such as fffff for a line in the output for tables, etc.) whether you have SAS installed on that computer or not. Submit this line of code at the beginning of your SAS session whenever you run SAS.
  • SAS_Functions.doc This document gives a listing of SAS functions from SAS release 8.2.
  • Homework assignments can be downloaded here:

  • epid759_homework1.doc
  • Sample SAS command files can be downloaded here:

  • pulse.sas This SAS command file shows how to import the Excel file: pulse.xls, and carry out some basic descriptive statistics using SAS.

  • Introduction to SAS Proc Mixed: CSCAR Workshop

    The Introduction to Proc Mixed (Longitudinal and Clustered Data) Workshop is presented by CSCAR.

    Click here to link to a web page where you can download the data sets and SAS commands for the labs for the Proc Mixed Workshop.


    Regression Analysis Workshop

    The Regression Analysis Workshop is offered by CSCAR.

    Data Sets for lab examples:

  • cars.sav You can Right-Click here to download the Cars.sav SPSS data set for the lab sessions. Do not open this file from the browser!
  • regression.zip Click here to download the Zip file containing the SPSS data sets and SPSS portable files for use in the afternoon lab for the regression workshop. Download the file to your desktop and unzip the data sets to a folder called "Regression" (you will have to create the folder) on your desktop.
  • SAS commands and the dataset for Box-Cox transformations are included below:

  • boxcox.sas SAS commands to figure out a good transformation for Y, using the Box-Cox method.
  • cars.por SPSS portable file to use in Box-Cox transformations example.
  • model_selection.sas SAS commands for model selection methods, including All Possible Regressions, Mallow's CP, and Adjusted R-Square.
  • fitness.por SPSS portable file to use in example of model selection methods using SAS.

  • Intermediate SAS Workshop

    The Intermediate SAS Workshop is presented in the fall and winter semesters by CSCAR.

  • labdata.zip Click here to download a zipped file containging data sets and SAS commands used in examples for the Workshop. Save this zip file on the desktop, and unzip it to a folder called labdata on your desktop.
  • sasdata1.zip Click here to download a zipped file containing SAS version 6 datasets (.sd2 extension) and a SAS version 6 formats catalog (formats.sc2) to be used in the workshop. Save this zip file on the desktop, and unzip it to a folder called sasdata1 on your desktop.
  • sasdata2.zip Click here to download a zipped file containing SAS version 9 data sets (.sas7bdat extension). Save this zip file on the desktop, and unzip it to a folder called sasdata2 on your desktop.


  • Biostatistics 510: Statistical Computing Packages

    I teach Biostat 510 in the Biostatistics Department at the University of Michigan School of Public Health . We cover simple data management tasks and basic statistical techniques using the statistical software packages, SAS and SPSS.

    The syllabus for 2008 can be found here.
  • syllabus_2008.doc
  • The Final Project for 2008 can be found here.
  • Click here to get to the final project assignment and the data sets.

  • In-class handouts for 2008 can be found here.
  • Click here to get to the in-class handouts for 2008.

  • Homework assignments for 2008 can be found here.
  • Click here to get to the homework assignments and homework data sets for 2008.

  • Data sets and commands can be found here:
  • cars.sav SPSS data set containing information on the Cars data, to be used in the demo lab.
  • data.zip Archive containing raw data sets, Excel file, tab delimited data, comma separated values (.csv) files, and SPSS portable files that may be read into SAS.
  • sascmd.zip Archive containing SAS commands that go along with the course pack.
  • Data_Descriptions.doc Descriptions of data sets used in this course, with lists of variables, etc.
  • sasdata1.zip SAS version 6 data sets (.sd2)
  • sasdata2.zip SAS version 8/9 data sets (.sas7bdat and .sd7)

  • General Handouts can be found here:
  • Import_Excel.doc This document gives step-by-step instructions on how to set up an Excel file for use with a statistical package and how to import the file into SAS.
  • save_sasgraphs.doc This document gives instructions on how to save/export a graph from SAS/GRAPH or SAS/INSIGHT into a Microsoft Word document or to Power Point.
  • fonts.sas This little SAS command file contains a line of code that will make your SAS output look good when printed from any computer (it will get rid of the funky-looking little row, such as fffff for a line in the output for tables, etc.) whether you have SAS installed on that computer or not. Submit this line of code at the beginning of your SAS session whenever you run SAS.
  • SAS_Functions.doc This document gives a listing of SAS functions from SAS release 8.2.

  • Arbor Research Proc Mixed Workshop (November, 2007)

    This workshop uses examples from our new book Linear Mixed Models: A Practical Guide using Statistical Software. The data sets and examples used in the book are included on this web page: Web page for Linear Mixed Models Book where you can also get information on a 20% discount on the book.

    Workshop examples and data sets are included in the zipped file below:
  • procmix.zip this zipped file contains data sets and SAS commands used in examples for the Workshop. Download and unzip this archive to a folder on your desktop called procmix.

  • ratpup_diagnostics.rtf this rtf file contains SAS ODS output from an analysis of the Rat Pup data using SAS Proc Mixed, along with diagnostic plots and the experimental influence diagnostics available in SAS 9.1.3.


  • SAS Data Step Workshop for Arbor Research

    This workshop covers parts of the CSCAR Intermediate SAS Workshop presented in the fall semester.

  • labdata.zip this zipped file contains data sets and SAS commands used in examples for the Workshop. Download and unzip this archive to a folder on your desktop called labdata.
  • sasdata1.zip this zipped file contains SAS version 6 data sets (.sd2 extension), and a SAS version 6 formats catalog (formats.sc2). Download and unzip this archive to a folder on your desktop called sasdata1
  • sasdata2.zip this zipped file contains SAS version 9 data sets (.sas7bdat and a version 7/8 data set .sd7). Download and unzip this archive to a folder on your desktop called sasdata2

  • bostfire_setup.sas this SAS command file contains syntax to read in the data for the Boston Arson Study, so it is ready to be merged.
  • bostfire_merge.sas Do you really want to peek?? This SAS command file contains syntax to read in the data for the Boston Arson Study, and merges it. Check this after you have tried to do the merge yourself!
  • da9972.bostfire this raw data file contains information about fires in the Boston Metropolitan area.
  • da9972.macensus this raw data file contains information on characteristics of Census tracts in the greater Boston area. It can be merged with the Boston Fire data.
  • ratbrain.dat this raw data file contains information on activation of a chemical in two treatments (Basal, and Carbachol) and three regions (BST, LS, and VDB) for five rats in Wide format.
  • rat_brain_restructure.sas SAS commands to restructure the ratbrain data set from wide to long format.


  • Biostatistics 600

    General handouts can be found here:

  • save_sasgraphs.doc This handout shows how to save a SAS graph from either the SAS/Graph window, or from SAS/INSIGHT, and import it into Word or PowerPoint.
  • Preparing Data Using Excel This web page from CSCAR gives an explanation of how to set up an Excel file for use with a statistical package, such as SAS or SPSS.
  • fonts.sas This little SAS command file contains a line of code that will make your SAS output look good when printed from any computer (it will get rid of the funky-looking little row, such as fffff for a line in the output for tables, etc.) whether you have SAS installed on that computer or not. Submit this line of code at the beginning of your SAS session whenever you run SAS.
  • SAS_Functions.doc This document gives a listing of SAS functions from SAS release 8.2.
  • Handouts discussed in class, along with SAS commands that accompany them can be found here:

  • b600_Read_raw_data.doc Handout describing how to read different types of raw data into SAS.
  • readdata.sas Commands for reading raw data into SAS.
  • b600_Import_excel.doc Handout describing how to import an Excel spreadsheet into SAS.
  • b600_descriptives.doc How to get simple descriptive statistics using SAS.
  • descriptives.sas SAS commands that demonstrate how to carry out simple descriptive statistics.
  • b600_use_permanent_data.doc How to use permanent SAS data sets.
  • useperm.sas SAS commands demonstrating how to use permanent data sets.
  • b600_save_permanent_data.doc How to save (i.e., create) permanent SAS data sets.
  • saveperm.sas SAS commands demonstrating how to save (i.e., create) permanent data sets.
  • b600_migrate.doc How to migrate permanent SAS data sets from version 6 to version 9.
  • b600_data_management.doc How to carry out simple data management tasks using SAS.
  • datamgt.sas SAS commands for simple data management tasks.
  • b600_missing_values.doc Handout describing how to set up missing value codes using SAS.
  • missing.sas SAS commands for setting up missing value codes.
  • b600_basic_stat.doc How to carry out basic statistical tests for continuous and categorical data using SAS commands.
  • basic_stat.sas SAS commands demonstrating how to carry out basic statistical tests.
  • b600_operators_functions.doc Basic information on how to use SAS operators and functions.
  • functions.sas SAS commands demonstrating how to use SAS operators and functions.
  • b600_insight.doc Basic information on how to use SAS/INSIGHT for data exploration.
  • b600_manuals.doc An annotated list of some basic SAS manuals.

  • SAS command files and Data sets used in class examples can be downloaded here:

  • sascmd.zip This zipped archive containes additional SAS commands that go along with class handouts.
  • sasdata1.zip SAS version 6 data sets (.sd2 files)
  • sasdata2.zip SAS version 9 data sets (.sas7bdat) and a SAS version 7 data set (.sd7 file).
  • b600data.zip Zipped archive containing Blank delimited (.dat) files, Comma delimited (.csv) files, Tab delimited (.txt) files, Excel (.xls) files, SPSS portable (.por) files, and SAS portable (.xpt) files. Save this archive on the desktop, and then unzip it to a folder called labdata.
  • b600_Data_Descriptions.doc Information on the data sets included in the archives: data.zip, sasdata1.zip, and sasdata2.zip.
  • Class exercises can be downloaded here:

  • Exercise1_2007.doc Exercise 1: Reading a data set into SAS and carrying out simple descriptive statistics.
  • Exercise2_2007.doc Exercise 2: Create a permanent SAS data set, and carry out some basic statistical tests.

  • Financial Engineering: Introduction to SAS

    Zipped data files and SAS command files can be downloaded here:
  • finan_data.zip Zipped archive containing SAS command files, Excel files, SPSS portable files, etc. Unzip the files in this archive to the c:\temp\finan_data folder.
  • sasdata1.zip SAS version 6 data sets (.sd2). Unzip the files in this archive to the c:\temp\sasdata1 folder.
  • sasdata2.zip SAS version 8/9 data sets (.sas7bdat) and SAS transport files (.xpt). Unzip the files in this archive to the c:\temp\sasdata2 folder.
  • General handouts can be found here:
  • Preparing Data Using Excel This web page from CSCAR gives an explanation of how to set up an Excel file for use with a statistical package, such as SAS.
  • fonts.sas This little SAS command file contains a line of code that will make your SAS output look good when printed from any computer (it will get rid of the funky-looking little row, such as fffff for a line in the output for tables, etc.) whether you have SAS installed on that computer or not. Submit this line of code at the beginning of your SAS session whenever you run SAS.
  • SAS_Functions.doc This document gives a listing of SAS functions from SAS release 8.2.
  • Lecture notes can be found here:
  • SAS Key Concepts. This handout gives basic information on using SAS in the Windows environment.
  • Simple Descriptive Statistics using SAS. This handout illustrates SAS commands for carrying out basic descriptive statistics for continuous and categorical variables, and some simple graphs, including histograms, boxplots, and scatter plots with regression lines.
  • Overview of Data Management Tasks using SAS. This handout gives basic information on using SAS for data management, including tasks such as modifying a data set by adding new variables, recodes of variables, subsetting data, selecting cases for an analysis, etc.
  • Basic Statistical Tests using SAS. This handout illustrates SAS commands for basic statistical tests, including one-sample and two-sample t-tests, such as chi-square goodness of fit tests, and chi-square tests of independence, and one-sample and independent samples t-tests.
  • Oneway ANOVA using SAS. This handout gives basic information on using SAS for a oneway analysis of variance.
  • Paired t-test Using SAS.This handout illustrates how to use SAS for a paired t-test.
  • Bivariate Correlation and Multiple Regression Analyses for Continuous Variables using SAS. This handout gives basic information on how to carry out linear regression analyses using SAS, including checking the model assumptions with graphical analysis of residuals.
  • Checking for Multicollinearity Using SAS. This handout illustrates using SAS to detect multicollinearity in a multiple regression analysis.
  • Regression Models for Binary Outcomes Using SAS. This handout illustrates using SAS for analysis of a binary outcome variable, using a logistic regression model.
  • Regression Models for Count Outcomes Using SAS. This handout illustrates using SAS for analysis of a dependent variable that is a count, using a Poisson regression model.

  • Quizzes and Answer keys can be found here, along with the appropriate SAS code for each quiz.
  • Quiz 1.
  • Quiz 1 Key.
  • SAS code for Quiz 1.
  • Quiz 2.
  • Quiz 2 key.
  • SAS codes for Quiz 2.
  • Quiz 3.
  • Key for Quiz 3.
  • SAS commands for Quiz 3.


  • Clinical Research Lab

    Data Sets and handouts for lab session:

  • demo.dta This is the data set we used in the first Stata Session. Right-click on this file to save it to your desktop to the Stata folder.
  • IntroStata.pdf This is the handout that Myra presented in the first Stata lab.
  • Group123.xls This is the Excel file made from the 3 groups data. Note taht missing values for the numeric variables were indicated by a period (.) in the Excel Sheet.
  • Group123.txt This is the text file created from the Excel file above. The text file can be input directly into Stata using the insheet command.
  • Exercise_May22.doc This is the *Corrected* exercise for the Stata lab on May 22nd.
  • Clinical Research Stata Exercise May22 2007.doc This handout contains the worked problems for the lab exercise on May 22, 2007.

  • Introduction to SAS Workshop

    The Introduction to SAS Workshop is presented in the fall and winter semesters by CSCAR.

  • intro_data.zip Save this archive containing data sets on the desktop. Double-click to open it. Drag files out as you need them.
  • intro_commands.zip Save this archive containing SAS commands on the desktop. Double-click to open it. Drag files out as you need them.
  • sasdata1.zip SAS version 6 data sets (.sd2)
  • sasdata2.zip SAS version 8/9 data sets (.sas7bdat and .sd7)

  • Regression for Non-Normally Distributed Data using SAS (Generalized Linear Models)

    The Regression for Non-Normally Distributed Data Using SAS Workshop is presented by CSCAR.

    Download the SAS commands and the necessary data sets listed below, to the c:\temp\glmwkshp folder. You will need to create this folder before you begin.

  • Lab Examples 1-5 Tecumseh Study commands: tecumseh_genmod.sas SAS commands for Tecumseh Study.
  • Lab Examples 1-5 Tecumseh Data: tecumseh.sas7bdat SAS data set for Tecumseh Study.
  • Lab Examples 1-5 Tecumseh Data in Excel: tecumseh.xls Excel File for Tecumseh Study.
  • Lab Example 6 Alligator Data commands: alligator.sas SAS commands for a log-linear model, with a categorical outcome (food preference of alligators), being predicted by alligator size, and the lake in which the alligators were located.
  • Lab Example 7 Ship Data commands: ship.sas SAS commands for the Ship Data (Poisson Regression with an offset).
  • Lab Example 7 Ship Data Set (Excel File): ship.xlsExcel data set to use for ship example.
  • Lab Example 8: Epilepsy Data SAS commands (data are included in the command file) epilepsy.sas Data and SAS commands for the Epilepsy study.
  • Lab Example 9: Tecumseh Study SAS commands to set up longitudinal data for GEE analysis. tecumseh_gee.sas SAS commands to set up the Tecumseh data in longitudinal form for GEE analysis.
  • Glimmix macro. glimmix.sas SAS commands to define the glimmix macro. Download this command file to your c:\temp\glmwkshp\ folder.

  • Epidemiology 556:

  • data.xls Click here to download the practice class data set.
  • epid556.sas Click here to download SAS commands from Class 1 of Epid 556. These commands show how to get basic descriptive statistics for a data set imported from Excel.
  • epid556class2.sas Click here to download SAS commands from Class 2 of Epid 556. These commands show how to import an Excel spreadsheet using SAS commands, how to get simple descriptive statistics, bar charts, scatter plots, correlations, and regressions. The calculation of new variables
  • Class2analysis.docClick here to download the SAS commands from Class 2 of Epid 556, plus the output in a Microsoft Word Document.

  • Epidemiology 552:

  • Epid552_Fall2003.doc Instructions for getting data from American Factfinder and Running Commands in SAS.
  • age_sex.xls Excel file containing Age and Sex Distribution for United Stages, Michigan and a sample County.
  • setup_age_sex.sas SAS command file to read in the AGE_SEX.xls file and do cross tabs.
  • hospital.sas SAS command file to read the hospital discharge data set.

  • How to Import an Excel Worksheet in SAS Release 8 for Windows.

    Instructions for importing an Excel 4.0 worksheet called Pulse.xls and saving it as a temporary SAS data set are included in slides shown below. Click on any slide to get an enlarged version.



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  • Go to File...Import.
  • Choose the File Type as Excel 4.0 Worksheet.
  • Locate and select the file using the browse button.
  • Save the data set and finish.
  • Check the log to be sure the data set was created.


  • Pictures of our Japan Trip, November, 2007.

    Click here to see our Japan Pictures.


    Pictures of fishing at the Outer Banks, North Carolina.
  • Fishing in Currituck Sound.
  • Landing a nice striped bass.
  • A nice striped bass.


  • Pictures of our Manistee River Kayaking Trip are available here.
  • Starting out beside the Manistee River North of Grayling.
  • A view of the Manistee River from our cabin.
  • Kayaks parked for the night at our cabin.
  • Little flowers by the river behind our cabin.
  • Not a bad back door view!
  • The kayaking gang of five.

  • Pictures of our winter 2007 cross-country skiing weekend at Sleeping Bear in northern Michigan.
  • View of Lake Michigan from the Pierce Stocking Road on a snowy data at Sleeping Bear.
  • Another view of Sleeping Bear Dunes and Lake Michigan from the Pierce Stocking Road. Not as snowy on this day!
  • Skiing on a trail at Sleeping Bear. There were signs warning us about cougars, but I'm sure I could have outskiied them!
  • Snowy pine trees at Sleeping Bear.
  • Snowy hardwoods at Sleeping Bear.
  • Yes, this is the Sleeping Bear dune, and it was cold! Kids were actually sledding down this dune.
  • OK, so this is actually Jim and me skiing at Radrick Farms outside Ann Arbor.

  • Jim and I went to Tamil Nadu in the South of India in the spring of 1999.

    Click on the map of India to go to our India Page!

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    last updated: January 28, 2008