The Usability factor is instituted to guide web visitors through the completion of the conversion process.

FORBES: How to Make Your Web Visitors Do What You Want

The other part of the usability factor is called the process flow.

FORBES: How to Make Your Web Visitors Do What You Want

But down in the detail there were complex issues surrounding which elements of a design (in the form factor, in usability, and in what was called the trade dress) were truly protected by law.

FORBES: So Yes, The Apple vs Samsung Verdict Was A Big Mistake

And they will expect no sacrifice in usability, no matter the form factor.

FORBES: Time To Let Workers Bring Their Own Mobile Phones