Alan Cooper

to minimize mouse movement

Ideally, the application will save every single change as soon as the user makes it—in other words, after each keystroke. For most applications, this is feasible. Another approach is to keep track of small changes in memory and write them to the disk at reasonable intervals.

It’s important that this automatic save function does not affect the responsiveness of the user interface. Saving should be either a background process or performed when the user has stopped interacting with the application.