b*********h
发帖数: 1001 | 1 主要就是说人们在调查的时候普遍不敢说真话，必须要装B装政治正确，所以电话调查
很多人嘴上说不支持trump，但是等投票的时候反而投给了trump
文中举过以前类似的例子，这叫Bradley效应。
具体反映在，trump在网络上的支持率要高于电话调查的支持率，对3000 GOP投票者调
查显示网络上支持率能高出6%
In 1982, California voters were supposed to elect former Los Angeles Mayor
Tom Bradley as the state's next governor.
Bradley went into the election with a sizable lead over George Deukmejian.
Exit polls projected a Bradley win. But when the ballots were counted,
Deukmejian came out the winner.
Thus, the "Bradley effect" was born — named as such because many white
voters, who told pollsters they were voting for an African-American (Bradley
), ended up breaking for the white candidate (Deukmejian).
Could Donald Trump be the 2016 version of a reverse "Bradley effect?"
That's the theory of a new study released earlier this week by Morning
Consult, a DC-based data and technology company.
The study examined a mystery that has confounded polling analysts over the
past few months: Why does Trump perform better in online-based surveys than
polls that include live-telephone interviews?
The study posited that voters, when interviewed by pollsters via telephone,
are reluctant to admit their support for a controversial candidate whose
critics have painted him as racist. In self-administered online interviews,
on the other hand, they will be more likely to admit their support. And that
will more likely reflect their eventual decision in the privacy of a voting
booth.
"Much work remains to better understand which types of polls are actually
right in predicting Trump’s support levels, but a key implication of the
study is that many national polls may be underestimating Trump’s support
levels," the study concluded.
If true, the results could indicate that Trump's support in polls, which has
risen to new heights over the past few weeks, is actually understated.
Trump has climbed as high as 41% in a recent Monmouth survey of national
Republican primary voters. On average, he has a 17-point lead over his next-
closest Republican contender, Sen. Ted Cruz (R-Texas).
Overall, the study found that Trump performs about 6 percentage points
better in online surveys compared with those conducted by phone. In a sample
of nearly 3,000 Republican voters, the Morning Consult study found that
Trump garnered 38% support with online respondents, 36% with respondents who
were robo-called, and 32% among live-interviewed voters.
People's level of education may have something to do with whether they're
willing to openly back Trump in live interviews, the Morning Consult study
suggests. Polls have shown that less-educated voters have constituted the
bulk of Trump's support. But college-educated voters are more inclined to
back him in online surveys than by phone.
The research suggests this is due to the "social desirability bias" —
wherein, in live-survey interviews, respondents provide an answer they
believe will be viewed more favorably by others. It's the same bias that is
said to have fueled the so-called Bradley effect.
In the case of the "Trump effect," blue-collar voters aren't embarrassed
about their support — their support is consistent in both live-interview
and online surveys. But there's a clear difference among college-educated
Republicans.
"Among adults with a bachelors degree or postgraduate degree, Trump performs
about 10 percentage points better online than via live telephone," the
study said.
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Election Day
(REUTERS/Scott Audette)
Among pollsters and other political analysts, the theory makes some sense.
Public Policy Polling, a Democratic polling firm, conducts polls via
automated robo-calls. This method also reduces the chances of bias that
results from live-interview polling, since all respondents hear the exact
same questions posed exactly the same way through a technology called
Interactive Voice Response.
Tom Jensen, the director of Public Policy Polling, told Business Insider the
firm would often find results that would more accurately reflect the public
's attitude on the issue of gay marriage than more traditional, live-
interview polls. The speculated reason: Respondents are more likely to want
to appear sympathetic to the issue when talking to a real, live person.
"I think the theory that people are more reluctant to tell a live
interviewer they support Trump is certainly plausible," Jensen said. "For
instance, on gay marriage referendums over the years we always showed less
support for gay marriage than live-interviewer polls and were proven to be
right by the election results — because people thought the socially
desirable answer was to say they supported gay marriage and were more
comfortable telling us how they really felt."
Other experts, while intrigued by the idea, cast some skepticism on the
final thesis — the primary reason being that many online-based surveys have
proven unreliable.
Sam Wang, a polling expert and professor at Princeton University, told
Business Insider that he was "attracted to the idea." But he sent over a
list of caveats.
First, as he pointed out, the live-interviewer surveys featured slightly
different samples than the online polls. The live samples were comprised of
4% to 5% more men, 6% to 8% more from the 30-and-older crowd, and 3% more
Mitt Romney voters. If any of those groups are less favorable to Trump, the
end results could contain some bias.
Second, we don't quite know how Trump's results compare to other candidates
in the field. Is this phenomenon unique to Trump, or is it seen with other
contenders too, such as Cruz?
"Bottom line: I think the effect's no more than three percentage points, it'
s therefore not enough to make a difference in how we interpret surveys, and
it might disappear as the primary campaign season goes on," Wang said.
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donald trump
(Getty)
University of Michigan political scientist Michael Traugott, meanwhile, told
Business Insider that he wondered to what extent the "computer-literate"
sample represented the overall Republican electorate.
"This is an interesting piece of analysis of a cleverly designed study," he
said. "... One issue that is not discussed is the properties/quality of the
original sample drawn from an internet panel and how well they represent the
US population of Republicans or likely Republican voters. Even though the
experiment involves random assignment to the three different modes for the
candidate preference part of the study, I would wonder about how well these
relatively computer literate respondents represent the overall population of
interest."
Other polling analysts posit that support for Trump may, in fact, be
overstated: He often performs better in polls that feature Republican-
leaning independents, for instance. And many experts question whether Trump
supporters are likely to turn out to vote in primaries and even more
complicated caucuses next year.
If one thing is for certain, it's that Trump's candidacy is rewriting the
rules of politics and polling.
When Trump first rose to front-running status in the summer, a number of
theories prevailed: He had a "ceiling" of support. He wasn't looked upon
favorably enough to win. His poll numbers were overstated because of his
celebrity status and high name recognition.
Said Jensen, the Public Policy Polling director: "I don't think there's any
way to know for sure until we actually start doing some voting!" | s*********e
发帖数: 1814 | | k*********4
发帖数: 1147 | 3 支持床铺。刚刚加入Twitter to follow him。 | T*********I
发帖数: 10729 | |
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