I, too, agree it sounds like a slightly high nocking point. Something that can help explain tuning is the Tuning Guide from
www.eastonarchery.com.
And I commend you for wanting to find outsome of the finer things about tuning. You know, sometimes guys will say to just adjust your sight to compensate but there is a bigger issue than that. An arrow that is flying straighter (truer) will get better penetration, all things being equal. And boost your confidence in the long run, not to say anything about you just gaining the knowledge of how things work and understanding what to correct should something go out of kilter. Good luck.