Determining the appropriate sample size for a survey is a science but not necessarily an exact science. There are a number of factors that go into determining whether a sample size is appropriate. Your sample quality will vary depending on how well it represents the population you are studying and which recruitment channels you choose to utilize.
It is easy to be misled into thinking a survey was successful solely based on the number of responses. For example, you could acquire 2000 respondents at a BC Lions Game but the results wouldn’t be very accurate if you were doing a survey on seniors who love scrapbooking. Quantity is important but quality must come first!
Quality First
A high-quality sample will primarily include respondents who represent the population you are trying to study. Consider interest categories and demographic factors such as age, gender, income, education, renters vs owners, number of years in the community, life stage etc.
Quantity Second
The sample size typically recommended for most research studies is based on the industry standard 95% confidence level, with an accuracy of ± 5%. The confidence level refers to the likelihood that the final survey results will not deviate by more than a certain percentage from the actual population statistics.
The level of reliability of the final data can also be determined. Keeping in mind the desired goal of ± 5%, when conducting a study on a population size of 100,000 it would be necessary to capture 400 survey responses. In this case, the reliability of the results would be ± 4.9% at the 95% confidence level. This means that in 95 out of 100 repetitions of the survey, the results will not vary more than ± 4.9%. Below is the chart used to calculate the reliability of the information gathered at the 95% confidence level.
Be Confident in our Support
At The W Group, we utilize a research methodology that incorporates multiple recruitment and communication channels to engage residents in completing a survey. We analyze the research population before and during the survey. While the survey is live we smooth over language or approach to maximize completions without materially altering the reliability and validity of the data we’re collecting. Email us at communications@thewgroup.ca for more information and support on your next survey!