I've read articles with very conflicting arguments on t-shirt estimates. Neither article seemed all that credible so I thought I would bring this up here.
Are t-shirt estimates a good idea?
For those who haven't heard of this: T-shirt estimates are the practice of giving very vague and high level estimates when given vague, high level requirements, and no resources to estimate.
They are based on t-shirt sizes and as such are broken down into: XS, S, M, L, XL, etc.
I don't see any problem in them in principle. Requirement gathering, requirements research and proper estimation all require time. Much of the time, 'clients' can request premature estimates and the ability to use t-shirt estimations allows for answers that are obviously overly vague and can't be held to any standard. At the time, this satisfies the 'clients' as they at least something to base their thinking on.
Conversely, if you were to give the same client the answer of 5,000 hours but gave the stipulation that this was just a guess and put that in bold, red, and blinking text. You run the risk of the client 'forgetting' this and then getting upset when these hours change drastically when a proper estimate is done.