Former American Secretary of Defense, Donald Rumsfeld, once said:
As we know, there are known knowns. There are things we know we know.
We also know there are known unknowns. That is to say we know there are some things we do not know.
But there are also unknown unknowns, the ones we don't know we don't know.
You can express the need to look at additional 'parameters' or 'options' in many ways. here are a few that come to mind:
- Have you explored all options?
- What other input parameters does this system accept?
- Have you considered all the alternatives?
- Are there any other choices?
- Do you account for unknowns?
- Have you explored all avenues?
- Have you viewed the problem from all angles?
- Are there more inputs that we haven't covered yet?
- Have all the terms been defined?
Basically, take just about any verb that means 'searching', 'exploring', or 'viewing', and pair it with just about any noun that means 'option', 'path', 'route', 'input', or 'choice'.