"10 guidelines to consider when using overlays (Neil Turner)

Overlays, dialog boxes, modal windows, light boxes, call them what you want, that little window that pops up in the middle of the screen and demands your attention like a tantrum throwing toddler is a much used (and abused) design pattern. Within apps, on the web and even on mobile overlays are increasingly used to direct the user’s attention to a sub-task, without taking them away from the current screen. Used in moderation overlays can be a very handy and effective design pattern, but like strong Belgian beer or Krispy Kreme doughnuts use them too much and you’ll leave your users feeling decidedly unwell and nauseous. Ensure that your users don’t come down with a bad case of overlay poisoning by considering these 10 overlay guidelines. (uxforthemasses.com)