A Golden Rule of interaction design is that if you change an interface convention, the replacement had damn well be better than the convention you replaced. Demonstrably better. By this standard, OS Lion’s “Save As” replacement “Save a Version” fails. Epic Fail, in fact.
In Ye Olden Days of GUI (Apple’s Lisa and the Xerox Star), “Save” used to be “Save and Put Away” (Xerox Star) or (as an option with Save and Put Away) “Save and Continue” (Apple Lisa). “Save and Continue eventually just became “Save” while “Save and Put Away” vanished, probably once RAM and memory allowed for multiple documents to be open at the same time without processor issues. “Save As” seems to have begun in the 1980s as “Save a Copy as,” and eventually some applications had all three: Save, Save As, and Save a Copy as. (What the difference between Save As and Save a Copy As are unclear to me.) Eventually, as people understood the Save As paradigm and with the broad adoption of the Undo action, “Save a Copy as” has mostly vanished. You can still occasionally see “Revert to Saved” in file menus.
In any case, the mental model of Save As has been fairly stable for at least 30 years now. You change the document, then you give it a new name. Apple’s new model seems to be the reverse: I’m going to change this document, so I need to Duplicate it, then change it. Old versions inexplicably lock, although I’m at a loss for when and why. (At least I think this is how it works: the mental model makes no sense to me.) Ostensibly, this is because Apple has an autosave that let’s you go back to previous versions. They thought somehow this would obviate the need for Save As.
But this is not how most people work (or, more precisely, how we’ve been trained to work over the last 30 years). This change breaks the mental model hard and replaces it not with anything better, but with a paradigm that is very difficult to understand (and poorly executed to boot). Most people don’t need the previous version of their document open at the same time as the altered version. Versioning is what programmers do, not what normal people do. When I (infrequently) need the earlier version of a document, I’ll manually open it. When I initiate a “Save As” I’m explicitly saying “This is a new thing, made from the previous thing. It’s a separate entity, deliberately established by me, not a “Duplicate.” I don’t want to “Save a Version,” I’m really making a new version, often one that involves putting this new version into a different folder. With Save a Version, I’m ending up with all these weird copies of documents that are difficult to determine which one is the most recent. Is it the “copy?” I don’t know.
Here’s a test, interaction designers. If you can’t easily diagram the logic of a feature, no way in hell are users going to figure out the mental model of it, unless you provide some easy means of making a “false” model that nonetheless allows users to figure out what is going on. This feature can’t be diagrammed easily (I tried) and the terminology around it doesn’t provide clarity.
This is the first time in a long time I’ve felt something that makes sense only for programmers has made it into an Apple UI. There’s no way Steve Jobs signed off on this change. It’s either too complicated, executed badly, or explained poorly—or all three—and those are not attributes I expect from Apple design.