Error in interpretation on the Multilevel Modeling Notebook

Not really sure where to post this, but here it goes:


After cell 24, and having obtained an estimate for a the floor coefficient, it is stated that:

The estimate for the floor coefficient is approximately -0.66, which can be interpreted as houses without basements having about half (exp(−0.66)=0.52) the radon levels of those with basements, after accounting for county.

I think this interpretation is mistaken. The relationship between radon levels and floor is assumed to be linear.

y_hat = a[county] + b * floor_measure

What’s expontential is the probability of the radon level conditioned on a certain value of floor, but as floor varies, the expectation of radon levels varies linearly.

Either that or I’m terribly confused, which is always a possibility :slight_smile:

The radon levels are on the log scale, so the exp is to convert back to the nominal scale.