Good Toolbars and Mysterious Lights
Heuristic: Consistency and Standards
Good example: computer application toolbars
When you open up a desktop application, the menu bar has a number of options. Even though many various companies release these applications, they all maintain a fairly consistent set of standard labels. The furthest-left is usually the name of application and contains options like application-wide preferences. Then there’s the “File” button, immediately to the left, and after that comes “Edit,” even in applications with different purposes, like a web browser (Firefox), a text editor (Word), and a graphic edition tool (Pixelmator). Furthermore, they all group functions under the same categories, so you always know to find something like “undo” under the “Edit” section, and can use the same keyboard shortcut as well.
Bad example: door card scanners
There are many inconsistencies with the scanners we use to get into buildings. First of all, sometimes it is enough to hold your ID in front of the scanner, and other times you have to actually physically swipe it through the slot (such as to get into MD after hours, I believe), even though the scanners look the same. Additionally, the lighting system is very inconsistent. On some, yellow can mean “locked but you can scan in,” whereas it will then flash red or green to let you know if you scanned in correctly. However, if, like at MD, you scan the wrong side or it gets a bad read of the strip on your ID, it flashes red, even though when you re-scan slowly you can then get it to flash green and unlock.
Furthermore, some newer buildings use the all-black scanners, and some doors on the houses have both all-black large 1ftx1ft square scanners and these old gray ones. The problem is that the new black scanners have no yellow light, but sometimes they flash blue for unclear reasons (I think it’s accepting your card?). They are constantly red, but if you do scan correctly, then they turn green. If not, they beep but give you no visual feedback, leaving you to wonder if it read your card correctly or if you just don’t have permission. Plus, the “unlocked” state for the gray scanners involves just the green light, whereas the black scanners will flash green/red back and forth rather than staying green. Finally, for reasons beyond my comprehension, sometimes there are both gray and larger black scanners (like the main doors of main Quincy) but you can only get in if you scan the gray scanners, yet in other places you must use the large black scanners (like the main doors of Lev).
I would redesign the scanners to be very consistent. I’d make them all the same, and show only one light in the center (rather than having slots for the dimmed lights as well, like the current gray ones do). If the door was unlocked for anyone, it would always be green. If the door was locked but you could scan it, it would always be constant yellow. If it read your card, it would either flash green – you’re allowed in – yellow – for “did not get a good card read, scan again” – or red – “it read your card properly, and you don’t have access.” There would be no other lights or flashing to confuse people across different patterns, and only one scanner would be present at each door.