The spiral approach to software learning and development, which preserves a project history as a series of code snapshots or spirals, is used in this book.

The following three points are important in the spiral approach:

All of these three points are important in teaching and learning technologies.

Learning new software concepts and technologies is a challenging task. Learning in spirals, from simple to more advanced concepts but with concrete software applications, helps readers get a reasonable confidence level early on, and motivates them to learn by providing more useful applications. With each new spiral, the project grows and new concepts are introduced. A new spiral is explained with respect to the previous one. The difference between two consecutive spirals is that the next spiral has the new code introduced and the old code modified or deleted. This is named learning by anchoring to what we already understand. With a new spiral, we can come back to what we did previously and improve it. In this way, learning in spirals can touch the same topic several times, but each time with more details in a better version.