We show that simplified simulation models are not robust for indoor environments. Experimentation reveals that simplifications affect two MANET routing protocols in disparate manners. Furthermore, even within a single protocol performance trends vary erratically as parameters change. These results cast doubt on the soundness of MANET evaluations using simplified simulation models, and expose an urgent need for more research in this area.Evaluation of Multihop Mobile Ad Hoc Networks (MANETs) is usually performed through simulation. In these studies, it has been customarily assumed that simulation models with no obstacles are acceptable simplifications of the complex mobility and radio propagation conditions expected in actual MANET deployments.We evaluate the robustness of simplified simulation models for indoor MANET evaluation. A simplified model is robust if the performance results it yields differ uniformly from those obtained with the unsimplified model. Robust simplifications allow researchers to reliable extrapolate simulation results to real-life situations.