The development process of new features includes frequent usability testing with real users.

That's not what the vast majority of real users do.

Paper prototypes can be used for usability testing with real users.

Hackers who are also students may also be real users.

I'm not complaining out of randomness, but as a real user.

There you can post your question in the forum and get responses from real users of the website.

The walkthrough does not test real users on the system.

I've known some real users, and Rafe is not one of them.

Anyway, more than half the book is devoted to chapters explaining how real, not fictional, users have adapted the program to their needs.

Note that this need not be a real OS-level user.