When it is needed, that file can also be 'added to' the 'folders' "Teams"->"Alpha" and "Clients"->"XYZ Corp".
So, sort of like folders by a different name. But more like folders++. With complexity hidden until desired.
How files are physically stored is neither here nor there.
The problem with tags as pseudo-folders is that it breaks a core promise of "folders". Folders are a metaphor, and when you use a metaphor like files & folders, you're making a promise to the user. You're saying: "I'm making these things familiar to you so that you don't have to learn a new behavior."
To be clear, I have no problem with tags, and I do believe that the standard "hierarchy of folders" we use today is untenable with the volume of documents we generate, but extending folders is a bad idea.
The reason this breaks so badly is that users expect to preserve the basic move/copy dichotomy of a file/folder when we represent items as such. This expectation is rooted in the metaphor of a file or folder in the real world. I cannot place a physical document in to two folders without copying it. When I copy the document, changes made to the replica are not retroactively applied to the parent.
I have seen many Google Docs users lose hours of work because they used the "collections" feature of Google Apps incorrectly. An example, I've seen plenty of users do the following in an attempt to copy a file to a new collection in Google Docs:
* Locate an item that is already in a Collection
* Check the item in the Document List
* Click the "Organize" icon (it's a folder)
* Check the box next to another collection where they want the copy
* Click "Apply Changes"
The vast majority of the users I work with assume that the "same" document cannot exist in two places at once. They assume this because that is the way that files & folders have always worked. If an action results in the appearance of two documents, there are two documents. The item has been copied. It doesn't matter whether the language "copy" is used. The action is implicit in the learned behavior of files & folders.
Tags should be called tags. Users are smarter than you think. As engineers, we might be frustrated by the assumption made above, but in reality, the user is drawing an inference based on past experiences. They're applying conceptual knowledge that we taught them. That's "smart".
Implement a tagging system in a way that solves users' problems and they'll flock to it, but don't make it opaque by masquerading as something they already know.
Tags are for organization. People like to organize things in terms of visual hierarchies and landmarks. Raw tagging systems aren't popular, because most people don't memorize precise strings. [1] They remember roughly what directories look like and 'know where things are' based on whether they believe they can confidently determine "it" from "not it" while they navigate a structure.
e.g. Was the tag "RaptorX" or "2012 Predator" or "FooBird"? The user doesn't know. But they do know that when they navigate their project folders, they'll be able to pick out whichever project was fuzzily translated to "something like a bird of prey" in their mind. And they'll be able to do this as they navigate into a tree, as fast as if they had remembered exact strings. [2]
So when people are looking for something quickly, they're going to like the visual hierarchy. And when they're first saving a file [3], or when they're looking to open something when they 'know' where it is, they respond very positively to a visual hierarchy.
It's not about 'hiding' the fact that those 'folders' are tags. Or hiding the fact that files can live in multiple places (with multiple versions no less). We're still talking about new software that people would have to be trained on and told about its particular attributes.
So the fact that, yes, you need a dialogue to capture explicit intentions when doing move/copy operations in a pseudo-folder tag system is not a problem.
[1] Also why command line OSs and command line navigation are unpopular. People really like visual organization.
[2] In my experience, this is what people are really saying when they insist they'd rather navigate than search, even when they 'know' where something is. It's because they "know" where something is, in terms of landmarks in the visual tree. They know in a fuzzy way. And fuzzy searching is either frustrating, or requires nailing down enough tangential data (user/date/file type) that searching isn't any faster than navigating.
[3] Almost no-one wants to think about proper taxonomy or organization or an exhaustive document profile when they're drafting a new document. They just want to stash things somewhere where they can find them tomorrow and/or reasonably direct a third party to them. Proper organization is almost always a discrete mental process that happens after a document is 'done'.
I do like that idea though. Users often treat folders like tags. In a manner of speaking folders are tags, in that they label the contents. They just happen to be organized in a hierarchy. The tags get more specific as you dig deeper in to the tree.
I'll have a go at reasoning by anecdote. For some reason, the default behavior of the Finder search field searches your entire computer as you type. This always struck me as odd, because it is 180 degrees from what I wanted. I would frequently:
* Navigate to a relatively shallow point in a folder hierarchy
* Start searching from there, expecting that my search would be constrained to this location
I do this because I know (generally) where something might be, but I can't recall exactly where.
I ended up reconfiguring Finder to behave like this.
If you split the folder path by separator, you often get a set of tags. So, by drilling down in to a folder heirarchy, you're "scoping" your search by tags, getting more detailed as you go.
I think hierarchy may be the missing piece of the tagging puzzle. A hierarchy would provide guidance (and a visual component). It says, "start broad, then get specific". Imagine a workflow where you would navigate to a specific point in the tag tree, then create a document. Doing so would associate the document with the current tag set without any additional work. If needed, the user could add additional tags, drilling down as they go.
My most important point about "folders" is just that we should avoid referring to these new systems as such. If we want to make progress, we need to unhinge users' thoughts from old concepts.
Fair enough and I absolutely agree. Though be prepared for users to refer to them as such.
And as to tag hierarchies - that's where things have been going. At least, those things I follow (DMSs, CMSs-not-named-Wordpress). It also addresses the concern raised upthread of "Company A\Secrets\Company B vs Company B\Secrets\Company A". With hierarchical tags, this isn't remotely a problem.
If I'm keeping files on what multiple companies are up to I might have: Company A -> Secrets -> Company B and Company B -> Secrets -> Company A
To denote the secret files that each company is keeping about the other. The tags would be identical, but the folder structures entirely separate.
> module-1
> views
> other-thing
> views
> module-2
> views
> module-3
> viewsBut people have stubbornly resisted that for so long, I wouldn't hold my breath. [1]
[1] It seems just about every document management system since the 90s was designed under the "search, don't scan!" assumption, stubbornly clinging to theoretical efficiency and then grumpily (and often painfully) adding back in 'artificial' folder structures built from the tags for both file->open and file->save UI.
Also, this article gets the details wrong. For example, you certainly can nest folders in the real world. Take a personnel file cabinet, with a 2012 drawer, with a hang folder for each employee that contains a manila folder labeled timecards. That's 4 levels of nesting and it works fine.