Welcome fivethirtyeight.com!

Fivethirtyeight.com is a project by a Daily Kos contributor I've mentioned previously, here and here and which has some flaws, despite what I reckon are genuine attempts to avoid overstating Democratic party hopes for November.

I think it's a very good addition to the debate about what will happen, as opposed to what we might like to happen or wish would happen. As such, I have no hesitation in adding fivethirtyeight.com to my blogroll.

Here's what Poblano says about it all, taken from the site FAQ:

What is the significance of the number 538?
538 is the number of electors in the electoral college.

How is this site different from other compilations of polls like Real Clear Politics?
There are a few things we're able to do over here that these other sites haven't done. Firstly, we assign each poll a weighting based on that pollster's historical track record, the poll's sample size, and the recentness of the poll. More reliable polls are weighted more heavily in our averages. Secondly, we include a regression estimate for each state among our 'polls', which helps to account for outlier polls and to stabilize the results. Thirdly, we simulate the election 10,000 times for each site update, in order to provide a probabilistic assessment of electoral outcomes.

I'm not sure that RealClearPolitics doesn't already do the weighting that Poblano is doing, but either way there are likely to be some differences. See here for my praise for the RCP.

And we agree on Zogby:

OK, so just who are the most reliable pollsters? As of 3/13/2008, the weights assigned to the various polling agencies are as follows:

Survey USA 1.91
Selzer & Co (IA) 1.47
Field Poll (CA) 1.33
Rasmussen 1.30
Ohio Poll / U. of Cincinnati 1.24
Chicago Trib. / Market Shares 1.16
Mason-Dixon 1.10
Univ. New Hampshire 1.08
Public Policy Polling (PPP) 1.05
Research 2000 1.01
Mitchell (MI) 0.96
ABC / Washington Post 0.95
Insider Advantage 0.95
Quinnipiac 0.95
Strategic Vision 0.95
LA Times / Bloomberg 0.83
Star Tribune (MN) 0.81
FOX / Opinion Dynamics 0.79
CNN / Opinion Research 0.77
Suffolk (MA) 0.77
EPIC-MRA (MI) 0.75
Franklin Pierce (NH) 0.74
Farleigh-Dickinson (NJ) 0.71
Marist (NY) 0.69
CBS / New York Times 0.66
American Research Group 0.65
Zogby 0.64
Keystone (PA) 0.64
USA Today / Gallup 0.63
Public Opinion Strategies 0.63
Columbus Dispatch (OH) 0.50
Zogby Interactive 0.43