uni/year4/semester1/CT4100: Information Retrieval/assignments/assignment2/notes.md

Question 1

• Term suggestion: suggest terms that split the query space.
• E.g., jaguar: add the word car or the word cat.
• Don't focus on adding similar terms -- limited utility.
• Want to suggest a diverse number of terms.
• We want to suggest terms that are maximally dissimilar to each other while still be similar to the original query.
• Trade-off: could maximise diversity by picking random terms, but these would not be relevant to the query.
• Want to suggest terms that make a more specific query.

Question 2

• Term-term correlation: know co-occurrence of terms, e.g., t1 tends to occur with t2.
• User-user correlation: now that some users are making similar queries.
  • Could suggest terms that similar searchers are using that maybe they haven't.
• Ignoring temporal evidence.
• Multiple term suggestions in ranked order preferable.
• Consider relation to autofill in Google.
• Impossible to get fully right, looking for identification of data being used and a valid approach to using it, plus advantages & disadvantages of this approach.