In informal usage, the signal-to-noise ratio represents the ratio of useful and relevant information to superfluous or irrelevant information. We want to keep the noise down and the signal up, and the content must be rich enough and appropriate enough for the context. But each context is different. Though borrowed from the engineering field, the SNR principle can be applied to most communication design situations, too, such as building a webpage, a presentation slide, a poster or billboard, etc. The details of how much text and other visual content you actually use depends on your medium and what you're aiming to do, but the principle is the same: make sure your target audience gets the key message easily and quickly and don't tick them off with superfluous detail that amounts to no more than distracting noise.
Japan: the land of Zen simplicity and visual overload
Japan is a wonderful place. Some of the best graphic design treatments in the world are done right here. And some of the most chaotic and mad examples of graphic design and communication are also right here. If you have been to Japan you know exactly what I am talking about. Every student of design should take a study trip to Japan for a month or a year. In Japan we have a 2000 year-old culture steeped in aesthetic appreciation and tradition juxtaposed with modern, fast-paced city centers which give one the feeling of living inside a pinball machine. Insane and yet stimulating and even inspiring...most of the time.
In Japan I have found some of the best (worst?) examples of visual noise. Noise is so common in many retail settings that it's simply accepted as the norm. It's no wonder some of the ugliest, most confusing PowerPoint visuals are also found in Japan. It's all around us.
One example of clutter and noise that both fascinates and annoys me is the point-of-purchase displays found in many electronic shops. Yesterday, for example, we were out shopping for a new refrigerator. We want it to be energy efficient and with a beautiful stainless steel finish. It must look good and fit with our current interior design. But as you can see from the photo below, it's very hard to imagine how this expensive appliance will look or "aesthetically fit" in our kitchen. Moreover, while the price is easy to find, it was often hard to locate the most basic information such as its exact size or energy consumption, etc. in the sea of crap pasted to the front of the appliance. The information was there, but it took effort to find it. Besides the visual noise, of course, there was the loud background music featuring the store's theme song and the shouting of enthusiastic salespeople with megaphones -- if you did not speak Japanese, you'd swear by their tone and non-verbal cues that they were yelling at you to get the hell out of their store!
Above: A snap taken at Yodobashi Camera in Osaka. How long did it take you to figure out you were looking at two refrigerators?
Above: The dining table in a design-oriented furniture store gets it. We need to imagine how the piece will look (and feel) in our home. The specs and details are there in a small sign, easy to find without searching.
Poster design: the noise continues...
Advertising posters also run the gambit in Japan. The picture below is of a poster on an Osaka train that I snapped yesterday on the way home. The poster (about 60-70cm wide) is encouraging passengers to take a trip to Gold Coast, Australia. Some of the type is no bigger than 10-12 points; I had to stick my nose to the glass to even read all that detail. Good poster design should (1) be noticed, (2) be understood, and (3) be remembered (and hopefully get the viewer to take action). I have no evidence or proof, but I can not imagine this poster was very effective at getting more business. At the very least, though, this poster deserves to be in the hall of fame of ugly poster design.
In defense of the designer, this poster is a classic example of design-by-committee; the actual designer probably became no more than a computer operator with the client saying "Add this!" "Don't forget that!" "Where's the &^*#@! koala bear?!" and so on. Sadly, this poster resembles some design-by-committee PowerPoint slides which I have seen all too often in Japan. Often the default is: "When in doubt, add more."
Graphic design -- good and bad -- is all around us. Even non-designers can learn by observing the various graphic design examples in the real world with a critical eye.