I'll bet it wasn't the concept of directories that those secretaries of yours had trouble with. I'll bet that they simply weren't told that they existed and the

I'll bet it wasn't the concept of directories that those secretaries of yours had trouble with. I'll bet that they simply weren't told that they existed and the computer offered no hints and that when they were told, they understood it readily. My mom frequently has trouble with directories but it's not the concept she has trouble with. It's the fact that the filesystem is so huge that it's hard to manage and there is no way she keep where everything is in her head. The fact that operating system files, application files, and user created files are mixed rather indiscriminately is probably the biggest problem. Also photo-managing applications trying to make things simple by saving files but not telling her where they put them leads to a lot of confusion. But the idea of files and folders she has not trouble with; it's the difficulty of navigating an impossibly huge and insufficiently mapped directory structure that she has trouble with. The concept of folders is pretty straightforward: "Everything has its place and there's a place for everything." People naturally organize things through place and directories create a semblance of 'place' for abstract pieces of data. (Place is actually such a powerful concept in the human mind, that the Jesuits used to memorize complicated arguments and passages by going for walks and assigning concepts to different locations on the way.) Tagging and search based systems while technically more powerful, I think would actually be more confusing not less because the concept is not as intuitive.