…may not be a good way to start testing.
I heard a programmer use this metaphor to describe the testing habits of a tester he had worked with.
As a tester, taking all test input variables to their extreme, may be an effective way to find bugs. However, it may not be an effective way to report bugs. Skilled testers will repeat the same test until they isolate the minimum variable(s) that cause the bug. Or using this metaphor, they may repeat the same test with all levels on the mixing board pulled down, except the one they are interested in observing.
Once identified, the skilled tester will repeat the test only changing the isolated variable, and accurately predict a pass or fail result.