Jakob Nielsen, Ph.D., is a retired principal and co-founder (with Dr. Donald A. Norman) of the Nielsen Norman Group. Jakob established the "discount usability engineering" movement for fast and cheap improvements of user interfaces and invented the heuristic evaluation method.
Over the past decade, usability improved by 6% per year. This is a faster rate than most other fields, but much slower than technology advances might have predicted.
Most mobile applications are used only intermittently, so they must be especially easy during initial use. In particular, upfront registration shouldn't be required before users experience an app's benefits.
It's more difficult to conduct usability studies with experienced users than with novices, and the improvements are usually smaller. Still, improving expert performance is often worth the effort.
Usability is like cooking: everybody needs the results, anybody can do it reasonably well with a bit of training, and yet it takes a master to produce a gourmet outcome.
The human brain is not optimized for the abstract thinking and data memorization that websites often demand. Many usability guidelines are dictated by cognitive limitations.
The granularity of user decisions is much finer on the Web, which is dominated by the instant gratification of the user's needs in any given instant. Content must cater to this rapid pace.
Agile projects aren't yet fully user-driven, but new research shows that developers are actually more bullish on key user experience issues than UX people themselves.
Usability studies of corporate content distributed through Twitter, Facebook, MySpace, and LinkedIn: users like the simplicity of messages that pass into oblivion over time, but were frequently frustrated by unscannable writing, overly frequent postings, and their inability to locate companies on social networks.
