Bug Hunting Strategies?

Question

Let\'s say you have a bug that was found in functional testing of a fairly complex part of the software. It could stem from bad/unexpected data in the database, middle-tier cod

Answer 1

My order:

1. Look at the code of 1-2 most likely causes (chosen based on gut feeling).
2. If nothing is found, execute the code in debugger (or if not possible, insert debugging/logging statements to the code).
3. If nothing is found, call somebody else and repeat steps 1 and 2 together with him/her.

Answer 2

First I try to understand the bug, then I do all things you suggest, in order based on gut feeling. This is really a trade-off of how certain you are of a specific cause, and how easy that is to test.

In addition, when I investigate a cause I try to directly add the really quick checks as I'm inspecting the code anyway (add some temporary debug output statements, add asserts and such)