Ever since LaFeminista proposed The KETI Program (Kos Engineers Technicians Inventors), I've been trying to figure out a Really Simple way to show what the difference is between this group and Scientists.
I think I've got one. I don't think it's the only one, so anyone with another try at the question is invited to argue about it in the Comments.
Scientists use terms like theory and hypothesis to describe how they think the universe, or parts of it, might work, always dependent on additional data. KETIs tend to like Rules of Thumb, which effectively say "this worked when we tried it before, so it's probably a good starting point."
Scientists like equations which can predict the behavior of materials and processes. Engineers like tables that show the actual behavior of materials and processes under varying conditions, so that they can grab the figures they need for a specific project without worrying (too much) about whether they will transfer. Anomalies in the data are acceptable because they warn you away from areas likely to cause your work to crash and burn.
And, of course, the two groups are joined at the hip, as it were. A huge amount of scientific work has been based on the tables of engineering results, especially the anomalies, and some of the best engineering has come out of the application of those pesky theoretical equations to real problems. Cryonics, aerodynamics, computer/chip technology - all depended on strong, sometimes rocky, interaction between the two sets of disciplines.
Rules of Thumb are useful. But they are not Rules. And once you're used to making that distinction, you're a) a bit less tolerant of Rules, and statements that purport to be Rules, b) a bit more likely to try building something new, and c) more likely to be tolerant of the insistence of scientists on figuring out what's really going on.