[week 4] Muddiest Points

I always write long posts, yet this week I'll make the long story short:

• In slide 47, professor presented the Lucene term weighting and the SMART term weighting.. which is the term weighting for Lemur?
• I have been investigating about Gene databases, I wonder whether boolean search or vector space model are used for searching data in these collections. Is there any other popular way to index this data in particular?
  
• In slide 67, weights for terms in a query are "guessed"... which are the most popular ways to guess their importance, i.e., their weighting? Besides, is there any common scale (0-1, 1-10) used for this purpose?