Posts Tagged ‘ missing data ’

3 problems with mean imputation

December 6, 2017
By
3 problems with mean imputation

In a previous article, I showed how to use SAS to perform mean imputation. However, there are three problems with using mean-imputed variables in statistical analyses: Mean imputation reduces the variance of the imputed variables. Mean imputation shrinks standard errors, which invalidates most hypothesis tests and the calculation of confidence

The post Read more »

Tags: , ,
Posted in SAS | Comments Off on 3 problems with mean imputation

Mean imputation in SAS

December 4, 2017
By
Mean imputation in SAS

Imputing missing data is the act of replacing missing data by nonmissing values. Mean imputation replaces missing data in a numerical variable by the mean value of the nonmissing values. This article shows how to perform mean imputation in SAS. It also presents three statistical drawbacks of mean imputation. How

The post Read more »

Tags: , ,
Posted in SAS | Comments Off on Mean imputation in SAS

Visualize patterns of missing values

November 29, 2017
By
Visualize patterns of missing values

Missing values present challenges for the statistical analyst and data scientist. Many modeling techniques (such as regression) exclude observations that contain missing values, which can reduce the sample size and reduce the power of a statistical analysis. Before you try to deal with missing values in an analysis (for example,

The post Read more »

Tags: , , , ,
Posted in SAS | Comments Off on Visualize patterns of missing values

Create patterns of missing data

October 26, 2016
By

When simulating data or testing algorithms, it is useful to be able to generate patterns of missing data. This article shows how to generate random and systematic patterns of missing values. In other words, this article shows how to replace nonmissing data with missing data. Generate a random pattern of

The post Read more »

Tags: , ,
Posted in SAS | Comments Off on Create patterns of missing data

Visualize missing data in SAS

April 20, 2016
By

You can visualize missing data. It sounds like an oxymoron, but it is true. How can you draw graphs of something that is missing? In a previous article, I showed how you can use PROC MI in SAS/STAT software to create a table that shows patterns of missing data in

The post Read more »

Tags: , ,
Posted in SAS | Comments Off on Visualize missing data in SAS

Examine patterns of missing data in SAS

April 18, 2016
By

Missing data can be informative. Sometimes missing values in one variable are related to missing values in another variable. Other times missing values in one variable are independent of missing values in other variables. As part of the exploratory phase of data analysis, you should investigate whether there are patterns

The post Read more »

Tags: , ,
Posted in SAS | Comments Off on Examine patterns of missing data in SAS

3 Tips for Testing Large Data on Slow Connections or Escaping Upper Hell

May 27, 2013
By
3 Tips for Testing Large Data on Slow Connections or Escaping Upper Hell

Do you ever find yourself wondering if you are paying for sins from a past life while you wait for SAS Enterprise Guide to show ...

The post 3 Tips for Testing Large Data on Slow...
Read more »

Tags: , , , , , ,
Posted in SAS | Comments Off on 3 Tips for Testing Large Data on Slow Connections or Escaping Upper Hell

Welcome!

SAS-X.com offers news and tutorials about the various SAS® software packages, contributed by bloggers. You are welcome to subscribe to e-mail updates, or add your SAS-blog to the site.

Sponsors







Dear readers, proc-x is looking for sponsors who would be willing to support the site in exchange for banner ads in the right sidebar of the site. If you are interested, please e-mail me at: tal.galili@gmail.com
SAS and all other SAS Institute Inc. product or service names are registered trademarks or trademarks of SAS Institute Inc. in the USA and other countries. ® indicates USA registration.