This app, "Efficiency: How Do You Do This In SAS?", is one of a series of eBooks about SAS software programming focusing on frequently asked questions and answers about efficient SAS programming, both in program speed and maintenance, illustrated by code samples which can be sent by email directly from the app. It is designed to encourage users to contribute questions some of which will be included in future versions of the app. There are controls to select specific questions, move to the previous or next question, decrease or increase the font to suit the user's preference, and send emails requesting answers to questions not yet included in that version of the eBook.

The questions, with answers, included are:
1. Introduction
2. About the Author: Philip R Holland
3. What is Efficiency
4. Is code formatting important
5. Is SAS training important
6. What performance factors are important
7. Using look-up tables with Data Step Merge
8. Using look-up tables with PROC SQL
9. Using look-up tables with SAS Formats
10. Using look-up tables with generated IF..THEN..ELSE statements
11. Using look-up tables with generated SELECT..WHEN..OTHERWISE statements
12. Using look-up tables: which method is the quickest
13. How can I delete all the data sets created by my macro
14. How can I restore all the options changed by my macro