A control group is a section in an evaluation which has been obtain advertising free of change, so which you are able to compare outcomes using a section that's receiving a brand new effort, station outreach, etc..
A control group is a set of users at an evaluation which don't experience the analyzed variable, and so help to make a comparison data collection to measure effects. If you would like to get started working with a new station, or approaching consumers in a new manner, then your control group could continue to get standard marketing, not the new channel or strategy. If you find a rise in conversions which's statistically important for the analyzed group, in contrast to the control group, it is possible to presume your new strategy was successful. But when there's absolutely no substantial gap between conversions to the 2 groups, you might choose to try out a new strategy, since you are able to't conclude that the new strategy made a huge difference.
It's significant that control groups comprise of similar demographics because the remainder of your customers (so you don't unintentionally have largely girls on your control group, by way of instance, which adds yet another factor to the mix that you're not attempting to check). It's also wise to decide on a theory before you begin and concentrate on one factor to check, to create the results as simple to comprehend as possible.