For those who want to jump in quickly, "How do I?" topics provide "walk-through" lessons on the use of IFs. If possible, print the topic/lesson of interest to you and then follow it through carefully. It is usually best to proceed through the lessons in sequence. And taking at least a quick look at the Purposes of IFs before you start the lessons will be productive, because you must know a little about the components of IFs in order to use it effectively.

Begin each lesson when you are looking at the Main Menu of IFs, which you reach after you start IFs, see the logo of the world, and touch the Continue button.

• How do I display information that comes with IFs and from other scenarios? Lesson 1.

• How do I create an alternative scenario with IFs by changing one or more assumptions, running the model to compute the impact of the change, and displaying information from this run of the model? Lesson 2.

• How do I display and/or analyze data from the historic data set that comes with IFs? Lesson 3.

• How do I begin to change the character of IFs, by altering regionalization or relationships within the model? Lesson 4.