Because some people cannot distinguish colors reliably, we use redundant cues to ensure that any color-encoded information is also accessible through some other modality. For example, in most countries, traffic lights are stacked vertically, with red on top and green at the bottom so that even people who cannot tell red from green know how what to do. In GMail's "Message blocked" automated reply, the red light is shown at the bottom. People with normal color vision will get the message: "Stop!" But people with some color vision deficiencies will see it as a "Go"! This is an example where redundant cues instead of reinforcing the color-encoded information, contradict it instead.
Modern design uses color to communicate both information and mood. Several research tools exist that will automatically recolor web sites on the fly to make the color-encoded information content accessible for individuals with color vision deficiencies (CVDs). Unlike all prior tools, our SPRWeb system recolors web sites in a manner that preserves both the color-encoded information and mood.
The menu board at a local cafe provides a fun example of the failure to apply the mapping principle:
A while ago, if you wanted to get vitamin C from Boots (a British pharmacy chain), you would be presented with choices like these:
It is hard to see (and not just because the image is low resolution) that in one of these containers you would find orange-flavored tablets, while those in the other would be blackcurrant-flavored. Many customers failed to notice these flavor labels and brought home a product that was not what their loved one wanted. This design failed to prevent customers from making a mistake.
The handles for operating the sink and the shower valves in Statler Hotel bathrooms use nearly identical design language:
But they do different things! In the sink, the two handles control the amount of hot and cold water, respectively. In the shower, however, the left handle controls the volume of water while the right one is used to control the temperature: ...continue reading "Statler Hotel bathroom"
Great dishwasher, very quiet, too. But once you close the door and start the cycle, you have no way of telling whether the washing is still in progress or finished:
On Flickr, the user interface for adding a tag to an image is just a simple text box:
As a result, people make spelling mistakes entering their tags and do not even realize it. Consequently, for easy to miss-spell concepts, like Massachusetts, the photos are scattered over many miss-spellings of the tag: