Charles Miller describes how engineers express the level of difficulty of solving a problem (via Ron K. Jeffries). He has some great descriptions of each level of difficulty, which I found quite accurate:

* Impossible
* Unfeasable
* Non-Trivial
* Very Hard
* Hard
* Trivial

I’ve added “straightforward” to my language, which describes trivial problems that will still require some time to implement. I find it helpful in talking to non-engineers and to other engineers who might argue with my characterization of a given problem as “trivial.”