June 28 (Reuters) - A group of U.S. voters who were unable to choose between Joe Biden and Donald Trump before Thursday’s presidential debate delivered their verdicts after the contest and it was almost universally bad news for Biden.
Of the 13 “undecideds” who spoke to Reuters, 10 described the 81-year-old Democratic president’s performance against Republican candidate Trump collectively as feeble, befuddled, embarrassing and difficult to watch.
Focus groups aren’t meant to be used for gaining an understanding of a broad swath of the population. Focus groups are used for exploratory research, concept testing, and understanding the “why” behind opinions and behaviors.
If you want to generalize trends towards large populations, you’re going to need a large sample size. It’s statistics that suggests that many respondents will leave you with extremely low confidence in the outcome.
For example, if you are trying to judge the voting preferences of a population of 100,000 people, you’ll need 383 randomly sampled people in a survey to reach a 95% confidence interval. 13 is nowhere near the amount of people required to cover those that considered themselves “independents” before the debate.
That’s not to say this tells us nothing, but it’s by no means a predictive study.
Not to say this falls on deaf ears because I appreciate your actually understanding how scientific surveys work, but as you said yourself: These focus-groups of undecided voters are certainly warning-signs, and if it was flipped around, users would be up-voting this and BIden’s campaign would be touting this as a great thing.
I’m all for larger studies being conducted to show the damage done; the question will then be: How will you change your perception on what needs to be done?
And golly, if only we had large sample sizes of populations comparing Donald Trump and Joe Biden in battleground swing-states. If only we could then compare those numbers to their respective numbers in 2020… That, combined with said focus group insights, sure would be useful! /s