In a volatile marketplace — in which rates rapidly change, ads can be preempted (and then must be refunded) and candidates and outside groups pull ads on short notice — tracking who is spending what on campaign ads is not easy. Temple political scientist Robin Kolodny said a precise picture of TV ad spending will not emerge until early December when broadcasters disclose invoices that, unlike order forms, provide the costs and details of which political ads actually aired. "It's much easier to do it after the fact then it is in real time," she said.