« Trouble? | Main | A Fair Trade »
May 15, 2004
Apologies on the Dailies
Some readers (well probably all readers) have noticed that I stopped updating the Rasmussen daily tracking numbers about a month ago. The reason is that it seemed impossible to get an accurate count ... the only conclusion I could reach was that Rasmussen does either some serious weighting or some editorial adjustments to his numbers.
He published a weekly average along with a daily 3 day average. The weekly average equals S + M + T + W + Th + F + S / 7. If you go back, you can get the average for S + M + T and also for Th + F + S. If you multiply the weekly average by 7 and then subtract the 3 times the Tuesday average from that week and also subtract 3 times the Saturday average for that week then that leaves you with Wednesday's daily number.
Additionally, if you know one day's daily number you can also figure out the daily number for the 3rd day after that. W + Th + F / 3 = Friday's average. Th + F + Sat / 3 = Saturday's average. Thursday's daily and Friday's daily are a constant in both equations, the only difference is Wednesday and Saturday. So the difference in the Friday and Saturday average numbers times 3 is the difference between Wednesday and Saturday's daily numbers.
Suffice it to say that if you have three weeks of data you *should* be able to figure out every day's numbers. When I did this and when Rasmussen would let slip some of the daily numbers my data didn't correspond with his. So I figured what's the point? He's either making it up or I'm really bad at math. That said, it is fun to do and if someone with more time wants to tackle it I will give you a hint passed on to me by a reader. If you look at the source code of his page you can see the averages broken down to the decimal level...it's in the code for the graph on his webpage.
So today the poll says 46-45 Bush but the graph says it's actually 46.5 - 45.0 in the President's favor. So that's why I stopped updating it. It wasn't because Bush was pulling ahead (as seemed the case a couple of weeks ago) or that I think Kerry's got it in the bag, it's just because I think the source data is kind of junky and you know what they say -- garbage in, garbage out. And I try to at least be responsible for my own garbage on this site!
Posted by Chris at May 15, 2004 05:56 PM
Comments
Post a comment
Thanks for signing in, . Now you can comment. (sign out)
(If you haven't left a comment here before, you may need to be approved by the site owner before your comment will appear. Until then, it won't appear on the entry. Thanks for waiting.)