My General Complaint:
If you've had a gmail account for many years, either for work or personal, it's getting large enough that GMail's search is starting to break.
Anything word you can think of to type in will match tons of useless results. Eventually, as you try to think of more words to add, your results count goes to zero.
If you were lucky enough to have starred the email when you saw it, or can remember who might have sent it, or maybe the approximate timeframe, or maybe you think you might have sent the email in question from this account, you *might* have a chance.
A Tough Problem:
I realize this seems like classic precision and recall troubles, but Google is pretty smart, and they a fair amount of metadata, and a lot of context about me, so there's some potential fixes to hang a hat on.
And some of my ideas involve making labels/tags (Gmail's equivalent of folders), but that assumes that people are using labels, which I suspect many folks don't, or at least not beyond the default ones you get. Well... sure, but they DO have them, and there's an automated rules engine in Gmail to set them, so presumably a few people use tags / labels? (or maybe nobody does and, in hindsight, maybe a legacy feature!?) So, if you're going to have labels, and you've got even a few users who both with them, then make them as useful as possible. AND maybe make Labels more visible, maybe easier to set, more powerful, etc.
On To The Ideas:
1: Make it easier to refine search results.
Let's face it, as you accumulate more and more email, the odds of finding the email you want on the first screen of search results goes WAY down.
Google wisely uses most-recent-first sorting in search results, vs. their normal relevancy, in the GMail search UI. I'm not sure why, this seems like an odd choice for them given all the bravado about Google's relevancy, but I'm guessing it was too weird to have email normally sorted by date in most parts of the UI, but have it switch back and forth between relevancy and date as you alternate between search and normal browsing. Also, maybe they found it's more likely you're looking f or a very recent email. You could fold "freshness" into relevancy calculations, but just respecting date keeps it more consistent.
Yes, GMail does have some search options... I'll get to those, but suffice to say they are very "non iterative".
Other traditional filters should be facets as well. "Sent" emails, date ranges, "has attachments" (maybe even how many, sizes, or types)
2: Promote form-based "Search options" to FULL Facets
You can limit your search to a subset of your email if you've Labeled it - this is the GMail equivalent of Folders. But doing this is a hassle (see item 3), and you can't do this after the fact, once you're looking at results.
So, if you do normal text search, and then remember you labeled it, you can't just click on the tags on the left of the results. Those are for browsing, and will actually clear out you search terms. These should be clickable drilldown facets, perhaps even with match counts in the parenthesis, and maybe some stylizing to make it clear that they will affect the current search results.
Yes, there's a syntax you can use:
lebal:your-label regular search terms
It's a nice option for advanced users who are accurate touch typists and remember the tag name they want, but this should also be easy from the UI. Yes, there is an advanced search / search options forms, but this brings me to item 3...
(read the rest of the ideas after the break)