Research Tips

Statistically Significant Differences

Frequently, market research objectives relate to the examination of differences. For example, the attitudes of buyers of one brand may be compared to attitudes of buyers of another brand, or satisfaction ratings from this year may be compared to those from last year. Before acting on such comparisons, it’s important to know whether or not a particular difference is statistically significant.

Such differences are normally examined using surveys that include only a small sample of the target population (e.g. customers), and differences within the sample taken do not necessarily translate into differences within the target population as a whole. A statistically significant difference is one that is very unlikely not to be present in the target population as a whole (the exact probability varies with the level of statistical significance). When a difference is statistically significant, you can be much more confident that a meaningful difference exists than you can by just looking at two numbers to see if they are the same or different.