Political polls are hitting overdrive. Here's a quick guide to understanding them
Analysts explain why polls are important and how they calculate seat projections
On Sunday, Prime Minister Mark Carney is expected to ask the Governor General to dissolve Parliament and call a federal election. From that point on, Canada's federal parties will hit the campaign trail — and pollsters will be closely tracking who Canadians plan to support.
Political polls are a mainstay in any election campaign, and their frequency will increase once the election gets underway. So why do political polls matter, and what should you watch for when reading the results?
CBC Radio's The House spoke to two poll analysts to explain.
What should you check first?
Philippe Fournier, editor-in-chief of 338Canada.com, said when he sees poll results, he first checks who actually ran the poll "because we know that pollsters are not created equal."
"There are really good pollsters in this country, but there are also some pollsters that have [a less-tested] track record as others," he told host Catherine Cullen.
CBC's Poll Tracker collects data from several Canadian pollsters, including Liaison Strategies, Leger, Ipsos, Angus Reid Institute, Nanos Research, EKOS Research, Innovative Research Group, Mainstreet Research and Abacus Data.
Fournier also said he checks the sample size of a given poll, but the figure is often between 1,000 to 2,000 people with the occasional big sample size of 4,000 respondents.
Those larger sample sizes can allow pollsters to have a clearer idea of regional support, Fournier said, since there are more respondents from various provinces and territories.
How are seat projections calculated?
Poll aggregators like CBC's Poll Tracker include an estimated number of seats a federal party could win in an election. How does that work?
Éric Grenier, who runs TheWrit.ca and CBC's Poll Tracker, said his system takes the results from the previous federal election, looks at how polls have changed since that time and "swing[s] the results in each riding across the country to the same extent."
"If a party's doubled its support in a region, then you double their support in each riding within that region," Grenier told host Catherine Cullen. "And that gives us a pretty accurate beat on who would win the most seats."
It's not a perfect system and there are going to be individual errors, Grenier said, "but it's a useful tool to try and understand an election campaign."
According to CBC's Poll Tracker, the Liberals lead the Conservatives by a razor-thin margin in the polls — and the Liberals currently control the federal government.
With those conditions, Grenier said the Liberals could form government again.
"If you see a poll that has the Conservatives and Liberals tied, it might mean that's neck-and-neck, but it doesn't mean it's the same chances both sides will win," Grenier said.
Why are political polls important?
Grenier said political polls are "not necessarily something that is supposed to tell you how to vote or who is going to win."
Instead, he added, they show who is leading and "often explain what a lot of the parties and the leaders are doing in the course of a campaign."
"When you're a front-runner, you're going to act differently than when you're trailing. When you're way behind, you're going to act differently," Grenier said.
Fournier said when polls are "conducted properly by professionals, they constitute the most objective information you will ever have about a campaign."
Parties buy advertising and rally their supporters to influence voters and spin the news their way, Fournier said. But if polls are done correctly, they'll give Canadians "the score of the game."
"That's why I like following the polls so much, because it rings. It tells the story of the campaign," Fournier said.
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