Limitations

What this study cannot establish

  • The search provider, index, crawler, embeddings, personalization, retrieval stack, ranking features, or refresh schedule were not exposed.
  • Result behavior cannot prove that there is literally a candidate-pool stage followed by a reranker; that remains a weak architectural hypothesis.
  • Authority, page purpose, internal links, topical depth, freshness, and entity clarity are correlated on live pages and were not all isolated causally.
  • The retained block and unique-URL totals exclude the earliest 25 analyzable calls, so they are lower bounds rather than complete-corpus totals.
  • Four native opens were limited by a cache miss, timeout, or internal error. Their original result blocks still count as observed placement.
  • The corpus is substantial but finite and time-bounded to August 24, 2026. Search outputs can change after the capture window.
  • Quoted First publishes and benefits commercially from the study. No customer outcome, independent validation, ranking promise, or causal placement claim is made.