Ammar, > If an extra query is not too expensive for your situation, how about: > > scores.where(["standard_id NOT IN (?)", standard_ids]) This worked! Thank you! At this point, I'm glad it worked and have no idea how to tell if it is "too expensive." Can you recommend a resource that provides more info? > Do you really need self in those statements? Just searched for more info about when to use self (or not) and came up with this advice: "Never use self for retrieving values, since itÃÔ unnecessary and adds bulk. ...in the context of ActiveRecord." http://bit.ly/cVgYK This was helpful too: http://paulbarry.com/articles/2008/04/17/the-rules-of-ruby-self Thanks again for your help. :-)