Adjusting the test sensitivity of an experiment

You can decrease the minimum sample size required to reach statistical significance, although this decreases the confidence level. For example, you can reduce the minimum required sample size if you think it will take too long to reach statistical significance. This can happen if you are targeting an experiment to a webpage with a deep URL. You sometimes will not get enough traffic to reach statistical significance in the time you want.

There are other experiments for which you might want to increase the confidence level, even though it will increase the minimum sample size.

To account for this, you can increase the minimum detectable difference % to directly lower the required minimum sample size to reach statistical significance. That also means that the test will not be as sensitive, and will only show more drastic results.