Fifteen Seconds

I'm still noodling on the notion that consumers will give only about fifteen seconds to the average commercial message. Given that a consumer is exposed to thousands of messages per day, and has developed the ability to sort out what merits attention very quickly, chances are that some messages get a split-second glance before the viewer dismisses them as unimportant, while others command, by virtue of their relevance to the consumer, even more.

If we consider the 15-second average as a median rather than a mean, how much information can we get across to a subject in order to convince him to spend a longer amount of time paying attention to the rest of the message we want him to receive? It turns out, quite a lot.

The average American reads text at a rate of 250 to 300 words per minute, though it's suggested that if they wish to pay attention and are reading for comprehension, the rate drops to 200 to 230. Likewise, a person who is speaking at conversational speed (and a person can hear words as rapidly as they are said), they are communicating 150 to 170 words per minute. But again, trained speakers and broadcasters slow down from conversational speed, and aim for a rate of 120 to 150 words per minute.

Taken together, this means that in fifteen seconds, a user can absorb:

• 61-70 words or text information, if they are reading at a leisurely pace
• 50-58 words of text information, if they are reading for comprehension
• 37-42 words of spoken information at a conversational pace
• 30-37 words of spoken information at a broadcast pace

There isn't a guide for image information, but I expect that it depends on the complexity of the image. Chances are a person can recognize a picture of a can of soda, including the brand, in a seconds; but a dense information graphic might require longer to gather the meaning - which is largely a matter of design rather than comprehension (look at a stock chart, and you can tell instantly if the price is going up or down, and if there is much volatility).

My point being: fifteen seconds is sufficient time to communicate a considerable amount of information - almost a paragraph of written text, or two very long sentences of spoken data, or fifteen images of different objects and information graphics. If you can't catch a person's attention with that amount of data, chances are very good that you're either a rotten communicator, or have nothing of interest to your audience.