Dictionaries and Tolerant Retrieval

Introduction to Information RetrievalSec. 3.3.5General lissues in spell correction• We enumerate multiple alternatives for “Did youmean?”• Need to figure out which to present to the user• Use heuristics• The alternative hitting most docs• Query log analysis + tweaking• For especially popular, topical queries• Spell‐correction is computationally expensive• Avoid running routinely on every query?• Run only on queries that matched hdfew docs39