Causal effect of reduced visual clutter on navigation performance

Establish whether reduced visual clutter alone causes the performance gain observed with instruction-conditioned sparse semantic grounding, independently of changes in the semantic evidence available to the planner.

Background

SparseNav combines persistent geometric memory with instruction-conditioned semantic grounding, selectively acquiring only landmarks relevant to the active navigation instruction. The reported ablations show that instruction-related, on-demand grounding performs better than the evaluated dense-semantic alternatives.

The paper explicitly cautions that these results do not isolate the causal contribution of reduced visual clutter, because selective grounding simultaneously changes the semantic evidence provided to the vision-language planner. Determining whether reduced clutter itself produces the performance improvement therefore remains unresolved.