Canada is in the midst of a general election campaign, which will ultimately end at the ballot boxes today on April 28, 2025. In the time before that date, however, it is important for both citizens, parties, and candidates to know who’s in the lead. This is accomplished by polling, which gives us a clue as to who’s set to win in the end. The question remains, however, how exactly does polling work?
What is a Poll?
A poll, rather simply, starts with a question. In an election, such as Canada’s upcoming one, this question could be “how are you planning to vote on April 28th,” or, “which of the federal party leaders would you prefer to see as Prime Minister.” Afterwards, people are asked these questions.
According to Scott Keeter at Pew Research Center, the most common method of polling nowadays is through web surveys. People are usually contacted by phone or email and asked to fill out the survey on whatever questions the pollster may have. Telephone and paper-and-pencil surveys are also popular methods of gathering information. In the modern world, old-fashioned door-knocking has gone out of style.
The amount of data needed to accurately reflect the population varies depending on what the question being asked is, however, a sample size above 1,000 is usually enough to track trends across a nation. In order to reflect potential variability in society, pollsters often include a “margin of error” within a certain confidence level. For example, if the margin of error on a poll is 5 percent, with 98 percent confidence, that means that the pollster expects the real life data to reflect the polling data within plus or minus 5 percent of the data 98 percent of the time. Generally, the margin of error decreases with a larger sample size.
Bias
In order to account for some additional biases in sample size, a pollster may have to weigh their poll. This means adjusting the amount of influence each person’s response has on the overall poll, depending on the size of their voice. For example, if a certain demographic makes up 30 percent of the population, and yet only 10 percent of a poll is made up by that demographic, then the pollster needs to adjust the value of that 10 percent to reflect the size of that demographic in society. This helps to ensure polls are more accurate to reality.
There are, however, some dangers with polling. If a question is too leading, i.e, a question itself is presented in a biased manner in order to elicit a certain response, the results of the poll can be skewed by the pollster in order to back up a claim they wish to make. Additionally, a pollster could manipulate the end result of a poll by specifically choosing a sample that does not reflect the general population and instead reflects a point they are trying to make.
TL;DR
In the leadup to this election, polls will be a useful tool for determining who’s ahead or behind. But each poll must be taken with a grain of salt, first by considering the biases of its author and what they would have to gain from presenting the data in one way or another. Hopefully this article has helped you become a better poll reader.