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
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
In SAS procedures, the WHERE clause is a useful way to filter observations so that the procedure receives only a subset of the data to analyze. The IML procedure supports the WHERE clause in two separate statements. On the USE statement, the WHERE clause acts as a global filter. The
