Software testing aims at assuring software quality. Given the knowledge of the system under test, one can derive the test suites under various testing assumptions. Black box testing concerns the case when only the access to the interfaces is provided; white box testing, on the other hand, ‘assumes’ that the source code is given and can be inspected. The goal of the project is to compare these two paradigms and draw certain conclusions about the fault coverage, test suite generation performance, etc. The analysis is supported by the experimental evaluation.