We have an expression at work: Don't lose the O-Rings. For those of you unfamiliar with that turn of phrase, the first shuttle accident was attributed to defective O-Rings on Challenger's solid booster rockets. Little things, really. But their failure resulted in catastrophe.
So we use O-Rings metaphorically in-house to represent some seemingly inconsequential thing that, if omitted, would similarly result in catastrophe. It means "sweat the details"—because, quite frankly, they matter.
Not everybody takes this same approach in the development of their software, however.
Microsoft's Explorer, for example, will not do a Search into the Program Files folder, even though you've checked a special box that gives it permission to search "System" folders1. It doesn't tell you that it's not doing this, it just goes ahead and doesn't do it. So if that file you're looking for happens to be in a folder within Program Files, well, somebody's just gone and lost an O-Ring. Now, in fairness to Microsoft, one might argue that nobody should be putting user-sought files there, but that fails to appreciate the reality that software developers do, in spite Microsoft's wishes. (Irritatingly, some developers seem to do it because Microsoft doesn't want them to.) Despite admonitions not to, several applications that I know save user documents into their folder in Program Files. I know. I've installed a few of them, and it's irritating that Search through Explorer doesn't find them.
I don't mind that Microsoft made Search "smart" (and I use that term lightly...) because 90 percent of the time or more, users won't care that Program Files isn't searched. But by the same token, 90 percent of shuttle launches not resulting in catastrophe is not exactly something to be proud of. Really, Search needs to be open and honest about what it does and does not search. It should do the "right" thing (according to a clear majority of use cases) out of the box, but it should disclose that it didn't search some places (no, not as a MessageBox, and not as Clippie either) and give the user the choice to extend the search if they want to.
1 Yeah, I know, System folders doesn't mean "folders important to the system", but rather "folders with the System attribute set". Most users don't know or care about that fine distinction, though, and those that do need a label that's less ambiguous.