Menús que se mueven
"We found users follow a pattern: they decide what they are going to click on before they move the mouse."

Y
"Unfortunately the information in fly outs, rollovers, or dropdowns can't help users decide where to click because the information isn't available to users when they are making their decision. It isn't until after they've decided where to click that they see what the element has to say."

Todo en este artículo de 2001. 
¶ 4:05 PM