In this week newsletter the third statistical ghost: multiple comparisons.
As soon as you look at more than one metric (this can also be a segment), you increase your chances of seeing a false positive. To put it simple, every comparison you make has a chance of showing a false positive. So more comparisons means more false positives.
For example: if you segment your test to device type. There are 3 different devices: desktop, tablet and mobile. As a result the chance of a false positive increases from 5% to 15%.
What else in this newsletter:
- The decoy effect: how are you influenced to choose without really knowing it.
- The state of marketing training in 2019. Research done by ConversionXL.
- Summary of the Friends of Search 2019 event.
- New tool to measure sitespeed: speedmonitor. io
- Conversie Specialist training @ Online Dialogue
Enjoy your week.