- Experiments from planned designs, design data, and causal about changing outcomes. Experiments and comparison. All analytics rest on comparison.

- Is this the most important business outcome?
- How will we know? What are the pre-test outcome metrics
- Experimental units (they shouldn’t communicate, buffer between control and experiment)
- Statistically valid, “power calculation”; how much am i willing to invest to understand?

What’s the purpose of our experiment?






- Success / efficacy in testing required re-designing the site

- Testing the test required education on the new scoring process, which did not slow down the process but quickly conveyed info.



- The experiment on the left violates probabilistic equivalence because once you receive name and address from the two groups, you now know something about those two groups: One is interested in RED and the other has a low bar for giving up PII for money




