Who's not here?

Do you measure the effectiveness of your ministry by who is there... or who isn't there?

I wonder if it would be more effective to measure by who is not present?

This might let us know what types of kids we tend to miss, alienate or ignore.
This might give us a better read on how well we do follow-up.
This might help us keep a better eye on the kids that are hurting.
This might keep us humble and remind us that we're not about numbers but names.