Board Thread:General Discussion/@comment-6056721-20131021073309/@comment-17381246-20131022024807

I think Dipper is investigating the monsters by the orders they are numbered in Book #3. Though, I also think the creators want to make it seem like Dipper does "Dipper's Guide to the Unexplained" like a weekly thing and that these ones we get to see are just some of the episodes's he's made.