Should QA test from a strictly black-box perspective?

Question

Assuming that unit tests are handled by development, is there any reason for QA to have knowledge of the details of how a product works? By which I mean, do they need to kn

Answer 1

It absolutely makes sense for the testers to know as much about the implementation of the software as they can. That'll help them test better.

Black-box testing is a useful and necessary technique, but knowing a little bit about what's happening under the hood makes it easier to define the really interesting test cases.

The problem with relying on developers' unit tests for all your white-box testing needs is that developers, by and large, are not very thorough testers, especially when it comes to code that they've written.