All political eyes are focused on the U.S. Senate Race here in Washington state. Will 3-term Patty Murray–a Democrat–be beaten by the two-time Gubernatorial loser Republican Dino Rossi?
Friday, October 08, 2010– www.rasmussenreports.com leads with this header:
Washington Senate: Rossi (R) Inches Ahead of Murray (D)
First line: Republican challenger Dino Rossi has edged slightly ahead of incumbent Democrat Patty Murray in Washington’s U.S. Senate race.
They provide their data:
A new Rasmussen Reports telephone survey of Likely Voters in Washington shows Rossi with 49% of the vote, while Murray’s support stands at 46%. Three percent (3%) prefer some other candidate in the race, and two percent (2%) are undecided.
Unfortunately, their poll has a 4 percent margin of error. This means that there needs to be more than a 4 percent difference in order to draw a statistically sound conclusion that one is actually ahead (and there is still a 5% chance of being wrong). These polling results are too close to call–and that is what should have been reported if Rasmussen were being honest about this.
Of course, Murray should be nervous that she is not doing better in the polls but Rossi cannot assume that he is, in fact, ahead, based on 750 “likely” voters.
From a research perspective, there are a couple of things we would need to know. One is how they define “likely.” The second thing is what percent of those participating were Republicans and Democrats. The third thing is whether they tried to weight the data to balance the percent Republicans and Democrats who answered their survey with the distribution of Republicans and Democrats in the population. And if they did, exactly how did they do that? It is very likely that some error was built into this weighting.
Lastly, given Washington politics, it would be important to know whether the respondents were representative of the east-west divide; the east side of Washington tends to be more Republican than the West side, especially the King County population center.
While we all want to know how the elections are likely to go, there is the risk that polls can be distorted to create a spin that might influence actual voter behavior.
It is important to ask questions of research results.