Signal-to-Noise

=**Signal-to-Noise**=

toc

**Definition**
Signal-to-Noise, also Signal-to-Noise Ratio or SNR, is the "ratio of relevant to irrelevant information in a display" 1]. This term is borrowed from the more technical fields of radio and electronic communications, where SNR = signal / noise 2]. In design and communication problems, a high SNR is theoretically ideal.

As what the phrase "less is more" suggests, any "excess is noise" 3]. Noise results to a degradation to the message and can occur in many ways such as: selection of inappropriate charts, using ambiguous labels and icons, unnecessarily emphasizing items such as lines, shapes, and symbols, etc. 4].

> The data displayed is extremely simple, but the eyes have to work > pretty hard to get at the data. ||
 * [[image:http://www.presentationzen.com/presentationzen/images/original_1.jpg]]
 * ===**Figure 1. Low SNR**=== This is an example of an information graphic with low SNR.

If the item can be removed without compromising function, then perhaps the designer (or the person communicating this data) should consider minimizing the element or removing it all together. For example, lines in grids or tables can often be made quite thin, lightened, or even removed 5].

> Now, the message is clear and is communicated more effectively. ||
 * [[image:http://www.presentationzen.com/presentationzen/images/bar2.jpg]] [[image:http://www.presentationzen.com/presentationzen/images/bar3.jpg]]
 * ===**Figure 2.** High SNR=== This is a suggested solution for presenting the data in Figure 1.

Finding the Balance
However, John Maeda points out in his book //The Laws of Simplicity// that although reduction of nonessential elements is important, sometimes it is equally important to retain elements which serve to support the message at a more emotional level. This may seem contradictory to the principle of a high SNR, but sometimes, emotional elements matter (sometimes a lot!) First impressions are often based on aesthetics. How the design looks or feels to the viewers (or users, rather) will influence the way people think about or interact with a design 6].

Understanding what noise is and what excess is is an important design consideration. What is considered noise will depend on the context (i.e. An excess of noise can occur from either too much or even too little information) 7]. In the same way, use depends on our particular circumstance, audience, and objectives. SNR is a good principle to consider but should not followed blindly. It is important for designers to find the right SNR balance when creating visual messages.

> everything visually except that which is essential. Yet there is > emotion there too; the logo is large, colorful, and even > "playfully seasonal." ||
 * [[image:http://www.presentationzen.com/photos/uncategorized/google_2.jpg]]
 * ===**Figure 3. Google**=== The Google website is an example of a website that have reduced

Another way of illustrating SNR is through online discussion forums. Off-topic posts and spam are considered as "noise" that interferes with the "signal" of appropriate discussion. The wiki collaboration model, like this one, permits users to "moderate" content, ideally adding signal while removing noise 8].

//"Make all visual distinctions as subtle as possible, but still clear and effective." - Edward Tufte//

**Sources:**
[1],[3] Lidwell, William. //Universal Principles of Design//. Gloucester, Mass.: Rockport, ©2003. [2],[8] "Signal-to-noise ratio." Wikipedia, The Free Encyclopedia. 16 Jan 2008, 01:33 UTC. Wikimedia Foundation, Inc. 16 Jan 2008  [4],[5],[6],[7] Reynolds, Garr. "Signal-to-Noise ratio and the elimination of the nonessential." Weblog entry. Presentation Zen. 12 March 2007. 16 January 2008. Note: All images are from this blog as well.