Data cleaning 101

This paper form the Robert Wood Johnson Medical School outlines a step-by-step process for verifying that data values are correct or, at the very least, conform to some a set of rules through the use of a data cleaning process.

Contents

• A Sample Data Set
• Description Of The File Patients,Txt
• Checking For Invalid Character Values
• Using A Data Step To Identify Invalid Character Values
• Using Proc Print With A Where Statement To List Invalid Data Values
• Using A Where Statement With Proc Print To List Out-Of-Range Data
• Using User Defined Formats To Detect Invalid Values
• Checking For Invalid Numeric Values
• Using Proc Means, Proc Tabulate, And Proc Univariate To Look For Outliers
• Using A Data Step To Check For Invalid Values
• Using Formats For Range Checking
• Extending Proc Univariate To Look For Lowest And Highest Values By Percentage
• Creating Another Way To Find Lowest And Highest Values
• Checking A Range Using An Algorithm Based On Standard Deviation