We present the results of a controlled experiment aiming at analysing the role played by the approach adopted during an IR-based traceability recovery process. In particular, we compare the tracing performances achieved by subjects using the "one-shot" process, where the full ranked list of candidate links is proposed, and the incremental process, where a similarity threshold is used to cut the ranked list and the links are classified step-by-step. The analysis of the achieved results shows that, in general, the incremental process improves the tracing accuracy and reduces the effort to analyse the proposed links. © 2008 IEEE