Oh, if someone could answer this question I would be so grateful. Does anybody know? Based on my experience, it does not seem to matter what type of question/answer series you are involved or not involved. The system is quirky. I mean... one day I went through my account and "unfollowed" a bunch of stuff - hubs, hubbers, questions, forums, etc. The next day my score was pumped up to 99 (from 94) for a day. What? I had not written any hubs, nor asked or answered any questions the whole week. Virtually, for that week, I was inactive, as hubbers go. Nevertheless, my score jumped up.
On the other hand, there have been times when I have published several hubs, asked and answered questions, started and participated in forums - did it all, and my score went down. What? I decided it was of no use to worry about my score.
The only reason I cared about my score in the first place is because I use my Hubpages profile page as a portfolio address for clients to have as a reference. It kind of hurts my reputation as a writer when a client goes to my portfolio page and sees low scores. Not having the knowledge of what it takes to increase my score is somewhat harmful to my image. If it were not for that, I would care less about my score.