What to look for when comparing past and present survey results

Often, one of the ways you decide how to view and act on the results of one survey is by comparing past and present survey results. This gives you a way to evaluate how customer responses have changed over time, which may give clues as to market changes or how customers have responded to different steps taken by your business. There are several things you should consider when comparing past and present survey results.Consistency in Survey MethodsIf your survey questions or survey methods have changed over time, it can cloud your results, making certain responses seem more or less significant than they might actually be. For example, if your past surveys had leading questions and your new surveys don't, that may be an issue. Similarly, if you switched from a "Scale of 1-5" model to an "Agree or Disagree" questioning system, you'll have to work to match up the results of surveys given with the two different methods.Statistical SignificanceStatistical significance refers to the probability that the results are not due to chance, but rather some relevant variable. Every survey will sample a different set of people, who may differ in their responses for a wide variety of reasons. Your software should provide a way to determine whether or not results are statistically significant.Landmark Moments If you're comparing past and present survey results, the differences you see may be due to gradual changes over time, but they could also be due to landmark moments that occurred. Before you compare results, make a list of any relevant events that happened near either set of results, such as:

• Major news or weather events
• The release of a new product line, or closure of an old one
• Any major revamping of your marketing strategy
• A re-branding of your company
• Any significant events related to your business, which may have received press coverage

At the same time, it's important to remember that correlation does not imply causation. It's useful to line up major events with the dates of different surveys, but not necessarily enough to attribute the results of one survey to the presence of a certain event.Isolated Incidents vs. Overall TrendsWith this information, you'll be on your way to determining whether differences between your past and present survey results are simply isolated incidents or overall trends; you'll also be able to start connecting the results to recent events, although it's important to remember that correlation does not equal causation.