The fourth wall is a term that I became familiar with many years ago in a media studies class. It's one of my favourites. Traditionally, it refers to the imaginary fourth wall at the front of a theatre stage, where there is f course, also a physical back wall and two side walls. The first known use of this term is cited as being in 1807, so it’s hardly a new concept.
Actors aren't meant to cross this boundary and acknowledge that there are people beyond the wall, the audience. Yet breaking the fourth wall is fairly common. An actor might acknowledge the audience or speak directly down the camera, addressing people. This happens a lot in sitcoms, Scrubs for example. Pantomimes practically knock the fourth wall down with their audience participation. It happens in films too. Norman Bates looks directly at the camera right at the end of Psycho. The fourth wall is also broken in Fight Club, Ferris Bueller's Day Off, Amelie and many more.
On the web we don’t have walls but let's pretend we do and let's smash that fourth wall to smithereens with user testing, surveys and research. We can and should make our audience aware that we know they're there and we're listening. We're listening so that we can give them what they need, when they need it, how they need it, where they need it. Needs! How can we understand the needs of our audience if we don't acknowledge them and speak to them directly? We can't. We can only guess and an uninformed decision is a bad decision.
No matter what we're designing, building, writing content for, testing, all those projects have one thing in common. The fourth wall, an audience. We need to put them front and centre of our work, not relegated to being passive observers.