How to Increase My Sample Size

When doing a statistical analysis, the sample size is very important to the accuracy of the results. For example, if you were to take a survey to determine how many people in your hometown work in service jobs, the most accurate way to do that would be to interview everyone. However, that may not be possible. Using statistics, you could interview a much smaller number of people and extrapolate your results to apply to the hometown. A sample that is too small won't give you accurate results, though. To increase your sample size, it's useful to offer an incentive. According to research appearing in the "American Journal of Epidemiology," people joined a sample group up to 75 percent more often when offered an incentive.

• 1

  Plan your incentive. Successful incentives include entry into a lottery where participants may win a prize or a small cash reward for participation.

• 2

  Contact a large group of random people. With spam laws and telemarketing laws in effect, the easiest way to reach random people may be through the mail unless you have a large, established database of people who have agreed you can contact them by email or phone.

• 3

  Prepare postcards that explain the purpose of your survey, how recipients can participate in the survey, and how they can redeem their incentive when done. If you are using the telephone as a method of contact, prepare a phone script instead.

• 4

  Begin making contact. Plan to contact significantly more people than you need, because not everyone will respond.

• 5

  Contact potential respondents in waves. For example, you might begin by sending out 100 postcards. Based on how many new participants you add to your sample size, you may send out a second wave if you still need additional people. By taking this approach, you can manage your budget better and still reach the sample size you need.