Black/white box testing - what is it?

[Sofie]

I've been told I need to do black box testing and white box testing, but haven't been taught how or been told what they are. All I've been given is a few links, which don't tell me much.

Please can someone explain what they are?

Thanks.

[laserlight]

Based on what you have read, what is your current understanding of black box and white box testing?

[Sofie]

I think Black box testing is to do with knowing the expected outputs and white box testing isn't. Whilst I understand that, I don't understand how would I go about doing these in VB 2008?

[laserlight]

I think Black box testing is to do with knowing the expected outputs and white box testing isn't.
No. You need to know the expected output otherwise you have no way of knowing if the actual output causes the test to pass or fail. The difference is between being ignorant of the implementation and knowing the implementation, respectively.

I don't understand how would I go about doing these in VB 2008?
One thing that could qualify as black box testing is to create acceptance tests based on the specification. Then, based on the code (which could be written in parallel with the tests if it does not already exist), you figure out what input would cause control to go through the various paths in the unit, and thus write unit tests that would qualify as white box testing.