This is what happens when you break the mental model.
The absolute dumpster fire that is OSX’s trash can
You probably imagine that your OSX trash can functions like this, with files from your computer as well as external drives going into a single pre-deletion repository stored on your computer.
This is mental model resembles the concept of a briefcase. If you throw away a piece of paper in your house, it goes into your house’s trash. If you throw away a piece of paper straight from a briefcase, it will go to whatever trash can is closest. If you put your thumb drive into another computer, and trash a file on it, you can expect it will end up in that computer’s thumb drive.
On the other hand, perhaps you expect that deleting the file from a thumb drive will instantly make it vanish, with no stop in the trash can, as is the case with some Windows devices.
That still fairly closely adheres to the briefcase metaphor, because it is unlikely you would toss out a document straight from a briefcase unless you were already certain you wanted to get rid of it forever.
Here’s how the OSX trash can actually works.
As it turns out, with Apple, every external storage device has its own trash can. This is a bit of a problem in and of itself because it is already stretching people’s mental models of external devices to the breaking point. External storage is “data luggage” and luggage usually does not have a garbage can built in.
Now, it could be said that camping backpacks have special pockets for garbage so you don’t leave a trace, so perhaps this isn’t breaking the data luggage model just yet. That doesn’t mean it still isn’t a problem.
Files in a trash can still take up space on the drive, space that cannot be overwritten until the trash can is emptied. If you send files from your thumb drive to your thumb drive’s trash can without emptying it, and then put the drive on another computer that does not use the OSX file system, you won’t be able to empty it. If you try to put files onto the drive from there, you may not have enough space left on the drive. If you can’t get to a Mac, you’re screwed.
Oh, and one more thing: Apple hides the fact that each device has its own individual trashcan by making it look like there is a single can. Here is the scenario:
First, you drag a file to your trash can from the thumb drive window.
Now, the file is visible in the trash can.
If you pull the drive out of the computer, you might not even notice that the file is now gone from the trash can.
If you put the drive back in, the file will re-appear.
That’s right. Apple can’t even commit to the funky mental model they chose. Even though every storage device has its own trash can, they are all represented by the same icon and even the same folder. For instance, if you have 10 files in your Mac’s trash can, and you insert a thumb drive into the computer, and that thumb drive has 1 file, then now your Mac’s trash can has 11 files. If you want to delete the 10 files from your computer, but not from the thumb drive, you have to remove the drive first.
Don’t even get me started on the fact that dragging a thumb drive to the trash “ejects” it. Mac has been doing that stupid crap since the floppy disk days. Behold, the kings of UX!
- Choose a mental model that matches what users expect.
- Adhere to your mental model 100% of the time.