Survey Data: How Many Responses Do I Need?
Posted in Ask the Expert, Main Content on 04/13/2010 11:42 am by admin

Respondent
By Jeanne Hurlbert, PhD
Many of you have asked us,
“how many people do you need for an accurate survey?”
The answer isn’t simple, but I can boil it down for you, with some basic principles that should meet the needs of most businesses.
First, what do you want to do with the data? What questions do you need to answer and how complex do you need to get?
- For certain kinds of data analysis—for example, if you want to do complex analysis and “cut” the data lots of different ways–you need at least several hundred respondents.
- If you just want to look at frequencies, though–in other words, if you just want to know how many people are interested in a particular product or service–100 or so might be enough.
Regardless of how many responses you get, the CRITICAL issue is what the “survey geeks” call representativeness.
- That means that you hope the characteristics of the people who respond, as a group, “look” as much as possible like the people in your customer base, as a whole.
- So you hope, for example, that you get roughly the same % of men or women that you have in the customer base, the same age distribution, and so on.
- One of the things we’re going to do in our new membership site is show you how to get this.
Sometimes, though, you don’t want to know about EVERYONE. Instead, you really want to know about a particular group, or segment of our customer base.
- Maybe you want to know if the frequent buyers are interested in a membership site.
- In that case, if you’ve already segmented your list (using surveys and data from your shopping cart) to segment your list properly, you can go in and select that group, then send the survey invitation JUST to that group.
- That’s just one of many reasons that segmentation is so powerful.
The bottom line? Anytime we do surveys, we want to get as high a percentage of customers as possible to respond.
And it comes back to the mantra we give you over and over: The best way to get good information from your customers is to show them “what’s in it for them.”
- You do that by giving them an incentive to take the survey (a free report and a chance to win something cool, such as an iPod, for example) and by
- showing them clearly, in the survey and the invitation, that we’ll use the information they give us to give them more value.
To get a quick, easy SYSTEM for doing surveys this way, go here.
One of the big questions we get from people who haven’t started using surveys in their business is,




