[thingie]

That's just a name. It is of course not a natural science, but a formal one, as mathematics (it could even be a branch of maths). There are even other kind of sciences, social ones, like psychology (which many people wouldn't call a science, though for different reasons, after all it does study natural things, doesn't it?). And of course, there should be a distinction from engineering (electrical e., software e.), though boundaries aren't clear and never will be. If you had a better name for those different kind of sciences, call them in that manner. Also remember, that by saying that something is not a science, it might seem that you are implying that the branch is somehow inferior to the "actual science". (This is not the case, but it is going to be perceived as that.)