Biostatistics 510: Statistical Computing Packages Fall 2002 Information

Homework assignments for fall 2002 are included below:

  • homework1.doc SAS homework 1. Reading in an Excel file, creating a permanent SAS data set. Creating some new variables. Paired and indendent samples t-tests.
  • homework2.doc SAS homework 2. Using permanent SAS data sets. Selecting subsets of cases. Merging data sets. Transformations. Distributions of variables. Paired and indendent samples t-tests.
  • homework3.doc SAS homework 3. Note: This homework is due, Tuesday, Oct. 1st. Reading raw data from a file, creating new variables using recodes, setting up user-defined formats, oneway frequencies and crosstabs.
  • homework4.doc SAS homework 4. Simple and multiple regression. Regression using dummy variables. Scatter plots of variables.
  • homework5.doc SAS homework 5. Oneway and twoway anova problems, with post-hoc contrasts.
  • homework5key.doc SAS homework 5 key.
  • homework6.doc SAS homework 6. Logistic Regression problems using SAS.
  • homework7.doc SPSS homework 7. Read in an Excel file, compute new variables, descriptive statistics and graphs, independent and paired-sample t-tests. Also, split file and statistics by groups.
  • heartrate.xls Excel file to use for SPSS homework 7.
  • homework8.doc SPSS homework 8. Read in raw data, recodes, compute new variables, crosstabs, linear regression, logistic regression, oneway and twoway anova.
  • homework8.sps SPSS commands for homework 8.

    • SAS examples are included below:

  • ttest.sas Shows how to read in a raw data file, create subsets of data, merge files by matching, calculate independent and paired sample t-tests.
  • freq.sas Shows how to use formats for categorical variables, recode variables into categories, do oneway frequencies, crosstabulations and get appropriate statistics.
  • matchfreq.sas Shows how to carry out appropriate tests for matched frequency data, including McNemar's test of symmetry and Cohen's kappa.
  • regress.sas Shows how to carry out simple and multiple regresssion using Proc Reg in SAS, create and use dummy variables in regression, carry out tests on parameters from a regression, and get regression plots.
  • select.sas Shows how to use different selection methods for multiple regression, including stepwise selection, backward selection, all possible regressions (r-square), selection based on adjusted r-square, and Mallow's Cp. Printout of residual analysis and influence statistics for a regression model.
  • anova.sas Shows how to carry out a one-way anova and two-way factorial anova using SAS. Also shows how to get post-hoc tests.
  • logistic.sas Examples of how to carry out a logistic regression with continuous and categorical variables using SAS Proc Logistic and Proc Genmod. How to calculate a likelihood ratio chi-square test to cmpare a full vs. reduced model in SAS.

    • SPSS examples are included below:

  • example1.sps Examples of how to read in data with 1 record per case, and with 2 records per case. How to do simple descriptive statistics using SPSS, crosstabs and simple plots.
  • example2.sps SPSS example on how to do crosstabs, get chi-square test of independence, relative risk, and measures of association for contingency tables for unmatched data. Shows how to get McNemar's test and Cohen's kappa for matched data.
  • spss_example2.doc Word document containing SPSS commands and output for example 2 for those who did not get the handout in class.
  • example3.sps
  • spss_example3.doc Word document containing SPSS commands and output for example 3 for those who did not get the handout in class.
  • example4.sps Oneway and twoway anova and logistic regression.
  • spss_example4.doc Word document containing SPSS commands and output for example 4 for those who did not get the handout in class.