I'm working on a new hairstyle that has 2 hair groups...1 for the bangs and 1 for the rest of the head.  I've got the main body of the hair at the length I want it, but the bangs need to be longer.  But when I lengthen the bangs, it lengthens the rest of the hair as well.  How do I stop it from doing this?

You could create a new hair object for that part. Groups keep the same properties, I guess so many separate areas can have the same properties easily. Or, you could try to lengthen the bangs by using the brush tool, it will work but it's a little tricky. It will stretch them out if you pull on them with it.

Thanks Patrick.  I guess my only option is to create a new hair object.   I'm guessing this applies to shaders for the hair as well?  What the heck is the point of having hair groups if they all keep the same properties?   sigh  :(

I've used the brush tool a lot and it doesn't look to me like it lengthens the hair.  Yeah, it'll pull it out to it's full length (if you've got a curl to it, or wave, etc.), but not actually make the hair longer than it is.

Sorry, I answered too quick. There is a tool called the "hair length" tool. Set the length on the tool to how long you want the bangs, and then run the tool over the root of the hairs you want to lengthen and they will grow out. Make sure the tool radius isn't too large.