A picture is worth...

Pictures can be very powerful. However, that unbridled power can sometimes portray the wrong message a thousand times more efficiently than one word. Kathy Sierra demonstrates this on her Passionate Users blog (one of my faves).

The picture above is a sign posted at a local trailhead. What does it mean? (Getting it wrong, by the way, means a $50 fine.) It's supposed to mean, "Each human can have no more than two dogs under their control." (this is a leash-optional trail) And while most people could--after cocking their head to the side--figure it out, I have to laugh about what else this sign says like:

"You can have a German Shepard, and an Old English Sheepdog, but SPRINGER SPANIELS ARE STRICTLY PROHIBITED!"

Contrast this with a suggested alternative :

RECOMMENDATION:
Use only one breed of dog in the graphic. Or better yet, use an abstract representation of a dog rather than a specific dog type.

Having three different dogs is misleading--it makes it appear that the breed of dog matters, when the sign is about the quantity of dogs per person.

She then applies this understanding to web page design as well:

If two buttons on a website are blue with round corners, they'll be interpreted as having some common function. If one of them is a navigation button and the other is a transaction button, there's a problem.

She goes on to explain other considerations that make the new sign more effective.

It seems to make so much sense, yet this forethought is not put into a lot of graphics that are created. So much of advertising and design is based on the mood and message of the picture that often accompanies the text. If the image does not capture the attention of the viewer, the message is usually not seen. If it conflicts with the text, it just leaves the viewer confused.

Make sure that you use the right one thousand words.