IVEware: Imputation and Variance Estimation Software

Survey Methodology Program
Survey Research Center, Institute for Social Research
University of Michigan

T. E. Raghunathan
Peter W. Solenberger
John Van Hoewyk

IVEware (Imputation and Variance Estimation Software) can:

Perform single or multiple imputations of missing values using the Sequential Regression Imputation Method described in the article "A multivariate technique for multiply imputing missing values using a sequence of regression models" by Raghunathan, Lepkowski, Van Hoewyk and Solenberger (Survey Methodology, June 2001).
Perform a variety of descriptive and model based analyses accounting for such complex design features as clustering, stratification and weighting.
Perform multiple imputation analyses for both descriptive and model-based survey statistics.

IVEware is a set of C and FORTRAN routines that can be launched from SAS or run independently using data from many sources. IVEware is currently available for personal computers using the Microsoft Windows and Linux operating systems. The SAS implementation requires SAS 6.12 or higher. For the independent implementation see the Srcware references below.

IVEware includes four modules: IMPUTE, DESCRIBE, REGRESS and SASMOD.

IMPUTE uses a multivariate sequential regression approach to imputing item missing values. IMPUTE can create multiply imputed data sets.
DESCRIBE estimates the population means, proportions, subgroup differences, contrasts and linear combinations of means and proportions. A Taylor Series approach is used to obtain variance estimates appropriate for a user specified complex sample design. A multiple imputation analysis can be performed when there are missing values.
REGRESS fits linear, logistic, polytomous, Poisson, Tobit and proportional hazard regression models for data resulting from a complex sample design. The repeated replication approach is used to estimate the sampling variances. A multiple imputation analysis can be performed when there are missing values.
SASMOD allows users to take into account complex sample design features when analyzing data with several SAS procedures. Currently the following SAS PROCS can be called: CALIS, CATMOD, GENMOD, LIFEREG, MIXED, NLIN, PHREG, and PROBIT. A multiple imputation analysis can be performed when there are missing values. Unlike the other IVEware modules, SASMOD requires SAS.

IVEware was developed by the Survey Methodology Program at the University of Michigan's Survey Research Center, Institute for Social Research and is available to users without cost by download from http://www.isr.umich.edu/src/smp/ive/.

Please report bugs or send comments via e-mail to T. E. Raghunathan, Peter Solenberger, or John Van Hoewyk.

Download Documentation, Software, and Example

Documentation

IVEware User Guide

Srcware User Supplement

SAS Installation Guide

Srcware Installation Guide

Software

	SAS version	Srcware version
Microsoft Windows	ive_sas_windows.zip	ive_srcware_windows.zip
PC Linux 32-bit	ive_sas_pclinux32.tgz	ive_srcware_pclinux32.tgz
PC Linux 64-bit	ive_sas_pclinux64.tgz	ive_srcware_pclinux64.tgz

Examples

	SAS version	Srcware version
Microsoft Windows	ive_sas_example.zip	ive_srcware_example.zip
Linux	ive_sas_example.tgz	ive_srcware_example.tgz

Last updated 2 August 2007