Quick, define incidence.

Struggling to come up with a concise definition for a term that is rolling off your tongue on a regular basis? Don't worry, you aren't alone, and we have an answer for you!

But before I give you the answer (and so you will hopefully read this to the end), let me tell you why you should care. Incidence is a critical metric to understand for a couple of reasons. Ever wondered how big your potential market is? Ever wanted to know how much your study should cost? These are both factors of incidence. So, yes, it's a big deal.

The good news is that incidence is actually quite a simple concept stemming from epidemiology (the brand of medicine that deals with the incidence, spread, and control of diseases). The bad news is that it can be murky to figure out exactly how to define it depending on the data you have available to you. The simple definition is the base rate that someone contracts a disease. It is expressed as a percentage, so if someone says the incidence of flu this season is 5%, it means that 5 people out of 100 got the flu last year. So it is quite a simple concept, but…

In market research it can become cloudy for a couple of reasons. The first issue that can complicate incidence is discrepancies in how brands define the target consumer. For example, Brand X of milk might say the incidence of milk usage is 60% because they found that 60% of people drink milk weekly. While Brand Y may say the incidence of milk is 75% because they found that 75% of people drink milk monthly. In order to agree upon incidence, the definition of the qualifying consumer needs to be agreed upon.

Ever heard that you only get out what you put in? That's true for incidence calculations as well. Frequently, companies don't have access to an unbiased data source that they can use to determine incidence. This can become especially tricky in brands that play in smaller categories. Without a solid data source to figure out incidence, it is hard for these brands to determine the size of their market potential and associated research costs. In these cases, the precision associated with the incidence will be increased as knowledge about the category or brand becomes more available.

Hopefully you can now impress your colleagues with your clear understanding of incidence. Let us know below what other research terms vex you and we will attack them for you!