Definition

A21 §3: “Query drift: retrieval terms progressively depart from the original information need. Question drift: a provisional explanation becomes embedded in the definition of the problem being investigated.” Its example: “Why did it fail?” becomes “Why was the dosage insufficient?” A23 VI.C: “The latter can persist even when individual searches appear locally relevant.”

What it must not be confused with

  • Query drift, the IR term (LIT-1079), where the need stays fixed and the search leaves it.
  • Legitimate refinement. QUESTION entries refine one another on purpose. Refinement is announced and keeps the broader question; drift replaces it unannounced. CLAIM-189’s line between announced and silent change is the line here.
  • Concept drift as CLAIM-177 uses it, where a term’s meaning moves. Here the term can stay put and the question move.