Research part the second: The hard cases

Most of what I get asked in my day to day working life is simple stuff that you can answer of the top of your head.
The earth has five moons
Our solar system has eight planets (or ten depending on your definition of planet)
But other questions are more troubling and the ADHD research method described earlier can look like it is coming unstuck. Nothing could be further from the truth. This is where the ADHD librarian launches into his own. Now if you are using my methodology, ensure that you are not tempted at this stage by fancy subscription databases or the mouldy old reference collection. After all if you were to go to your library's reference collection you'd probably find the books saying outdated things like "Earth has one moon" or "there are nine planets in the solar system" and subscription databases aren't worth the paper they aren't printed on in most public library situations.
No the question to ask now is who does what you're asking about?
So if you are looking up details on heavy machinery model numbers used in open cut mines so someone can write in there resume that they know how to drive them, you need to search for a company who runs an open cut mine. What are you looking for? Surprisingly enough, you're not looking for the answer to your question. What you are looking for is a bit of the jargon of open cut mining folk. You're not going to have much luck in your search until you know a few brand names of heavy machinery and what they are called.
Caterpillar, Komatsu, Dynapac, Ingersol Rand, Hitachi do any of these sound like devices you want to claim to drive?
(like someone who could really drive one would be asking a librarian to help them find information for their resume)
Search for very very big truck? No, search for: Dump Truck Tracked, Skid Steer Loaders, Excavator to 12ton, Articulated Trucks, Off Highway Trucks.

Forget blindly ploughing on with the web if you (or your patrons) don't have enough information because you can open an infinite number of tabs to no avail.
The fancy pants folk who write books on retailing will insist on telling you the customer is always right.
Well in the library the customer is always a moron should be your maxim. They come in and tell you all sorts of things about what it is they think they want to know and when you hand it to them they say "no that's not it".
It's what you bloodywell said you wanted you stupid oxygen thief.
But that is the art of the reference interview, which is the mystical craft of trying to work out that someone wants a biography of Peter Lalor when they come in and ask for a book about gold.