Designing Friction For A Better User Experience

In experience design, friction is anything that prevents users from accomplishing their goals or getting things done. It’s the newsletter signup overlay covering the actual content, the difficult wording on a landing page, or the needless optional questions in a checkout flow. It’s the opposite of intuitive and effortless, the opposite of “Don’t make me think.” Having said that, friction can still be a good thing sometimes. In game design, for example, friction is actually required.
Articles on Smashing Magazine — For Web Designers And Developers