arXiv:2611.05437v1 Announce Type: new Abstract: Requirements review involves identifying inconsistencies and assessing change implications across distributed specifications. Motivated by needs raised in industrial project workshops, we investigate Req-Space, an interactive prototype integrating semantic exploration and traceability visualisation to support human-led review. We conducted a fixed-order, two-phase study with 20 participants, including 11 with at least three years of software or IT experience. Participants reviewed a fictional 40-requirement software specification and a guest-checkout change request, first using source documents and then revisiting the same tasks with Req-Space. During the supported review, 17 participants recorded at least one additional source-supported item or pair. Of 69 assessable additional units, 58 (84.1%) were judged supported by the source materials. Seven decision rationales were judged stronger in Phase 2, including five without a change in the decision category. Participants generally found the visualisations helpful, although workload responses were mixed and some misinterpreted visual relationships. The findings suggest that visual support can facilitate requirements exploration and decision justification, provided relationship meanings and source context remain clear. The fixed study sequence prevents attributing the observed changes specifically to Req-Space.