I'm having a situation with codependent filters. Lets use as example KAYAK flight filters. We have a filter named TIMES that lets the user select time range for flight take-off. In other filter we have AIRLINES where the user can select the desire airlines.
If the user wants to take off only in morning hours there are airlines that doesn't match that criteria because they only take off during night. The filters are codependent.
In that case:
1) Should we reduce the filterable options available in the Airlines to display only the options that match the take off time selected? Or ..
2) We just leave all the non-matching options there, although it is useless information?
It seems that most of the site goes for the number two. Kayak does, but, it is ok? How can we handle this?!
Thanks for your support