Power Analysis

Power Analysis

How do you know if your test results are legit? Well… the bigger the sample, the more reliable the signal. But how big is “big enough”? That’s where Power Analysis steps in! Power Analysis helps you figure out how many observations you need to spot a meaningful change.

But here’s the twist: The more subtle the change you are looking to detect… the MORE observations you need. More time. More patience.

Want to detect a tiny 5% change with 95% confidence? Buckle up. You’ll need 10,000 observations. That’s 5,000 per group.

If you don’t have that many, then you’ve got two choices:

• Hunt for bigger changes (like 20% instead of 5%)
• Or… compromise and lower your confidence (80% instead of 95%)

But can you compromise? That depends on how much risk can you carry? And how subtle a change do you NEED to detect? For example, in pharmaceutical trials, a tiny 5% side-effect increase can mean… life or death…. whereas in website redesigns, aim for 20% improvement. Go big.

Because in testing—as in life—it all boils down to this: Know what you’re chasing and know what you’re willing to sacrifice.