Using Quotas with Survey Software
Quotas let you determine the makeup of the people completing your survey in terms of their demographics and other characteristics. For example, if you think that men and women may answer your questions differently, you can use quotas to ensure that your sample contains approximately the same ratio between men and women as exists in your target population. Sophisticated survey software lets you create quotas. Free or inexpensive online services typically do not allow quotas.
You can use quotas to limit participants based on other criteria besides demographics. For example, if you are interviewing businesses, you can use quotas to make sure that you get the proportions of small, medium and large businesses that you desire.
You can base quotas on either the answers to survey questions or on information you have in advance about the people you are inviting to participate in your study. When you send out email invitations for people to complete a questionnaire online or call people for telephone interviews, you at a minimum have their email addresses or telephone numbers. Often you have some additional information associated with those addresses or numbers. You can use that additional information for quotas.
When you are basing a quota on an answer to a question, and someone gives an answer that puts them over the quota, you typically skip them to a message thanking them for their time. The message may also say that you want to ensure that different types of people are represented and that you already have as many of their type as you need. If you use these kinds of quotas, please base your questions on quotas near the start of your questionnaire. It can be very annoying for people to spend five minutes or more taking a survey only to find out they can’t complete it. This can be especially annoying to people who are taking your survey in part because of an incentive you offered them. Also be sure to prevent people from backing up to the quota question and changing their answer. Some people will likely try to do that.
When you are basing a quota on information you have in advance about people your survey software should make the process as easy as possible for all involved. When doing telephone interviewing, your software should not even present a phone number to an interviewer, if that phone number is for someone who is already over quota based on that information. If you have sent out invitations for an online questionnaire, people whose previous information makes them over quota should be taken straight to a thank you message as soon as they enter a password or click on a link with one embedded, without asking them to answer any questions.
A third kind of quota lets you limit the total number of people that can complete a survey. This kind of quota can be very important, if you are offering people an incentive to take your survey. Most researchers typically have limited budgets for incentives, and you don’t want to be obligated to hand out more than intended.
Sophisticated survey software lets you assign multiple quotas to the same project, intermixing all three kinds of quotas – questions, information in advance and total completes – as needed.