Principles exist at a higher level than any pattern. They can be considered patterns for the patterns, if you will. Each pattern, and each detail of interactive or presentational design, should adhere to each of these principles at all times.

Each section and chapter will begin with a discussion of the core principles for their sections, as well as other helpful guidelines that apply to those patterns.

Each of these principles could be discussed in great detail, and in fact the book could have been organized differently so each of them was a chapter, with patterns associated to it. We didn't go this way, and in the interest of clarity, the discussion of each of these is limited. If you are interested in further details on the rationale, these are generally discussed in greater detail within the patterns they apply to, as well as the chapter introductions.

Respect user entered data

Input is hard. Users slip. You have a new phone, or are borrowing it, and someone jogs your arm: suddenly minutes of typing is gone. Do whatever it takes to preserve user data. From saving as they type so autocomplete can bring it back, to not clearing forms on error, to planning for loss of connection. Consider contexts and plan for crisis and real-world behaviors, not benchtops and labs.

Mobiles are personal

While security is important, there is no longer the need to assume that maybe the website is being viewed on a library computer. Mobiles can be presumed to be one-device for one-person, and no one wants to have to regularly tell their device their name, their location or their favorite music. Only implement passwords, and clear personal information when required by law or regulation, and take other types of reasonable and transparent precautions to prevent misuse of information.

Lives take precedence

Phones are used glanceably, a tiny bit at a time, as people get on with their lives. Don't make things blink or otherwise change state, if it can be missed at a glance, for example. If you have to get their attention, make sure you can, as part of their life.

Mobiles must work in all contexts

Behave appropriately, or allow the user to make it behave appropriately, to make it work where they are. E.g. usually too bright at night, so hard to read that last email before bedtime. If the phone doesn't have a good way to change brightness, you app sure can. Even your website can just have a dark/light switch.

Use your sensors. Use your smarts

You can do the above for them. Why should anyone have to silence a phone for a meeting, when it knows where you are, and that you have a meeting in that room at that time? Mobiles can be better than computers, because of their personal nature and their sensors. Use them.

User tasks usually take precedence

Over schedules, etc. If typing an SMS, let them. Don't focus on a meeting maker, or a new SMS or anything else. Beep if you must. Throw a notification strip up. But don't take them out of process.

Consistency

Whatever the OS does, do that.

Respect for information

Basically just precision vs. accuracy. Grab lots of my blog posts for this. TMI2, other industrial stuff, digital vs. analog indicators, decimal places, "yesterday", "about 2mb" and CEP circles.