We conducted a quasi-experiment comparing the conformance to the test-driven development (TDD) process of one expert and two novice groups of programmers working in pairs. Besides an insignificant tendency of the expert group toward a higher TDD conformance and instruction coverage, we found that the expert group had refactored their code to a larger extent than the two novice groups. More surprisingly though, the pairs in the expert group were significantly slower than the pairs in one of the novice groups.