Details on Priors for Lift Test Calibrations

There are a few different settings you can use when using lift tests to calibrate your MMM. These settings impact how the priors are configured for converting the lift test results into the actual priors that are used by the modeling process. There are three options:

1. Gaussian
2. "Strict gaussian"
3. Uniform (this is really uniform-ish)
   1. This is a uniform-like distribution with soft edges. See image illustrating it below.
   2. You still give it a “point estimate” and an “uncertainty”, and the prior is roughly flat between point_estimate +/- 1.96*uncertainty, with 95% of the prior weight in that range and 5% outside.

An illustration of the uniform distribution: