14. [Optional] Notebook + Quiz: Other Encodings

There is a key difference between the binary 1, 0 encodings that you've been working with, and the -1, 0, 1 encoding system: In the 1, 0 coding system, comparisons are to the baseline category as we've discussed, whereas in the 1, 0, -1 coding system comparisons are to the overall average.

The coding has all been done in this notebook. In this optional concept, you may study the notebook and interpret the results in the quiz questions below.

Code

If you need a code on the https://github.com/udacity.

QUIZ QUESTION::

Use the two models you fit above to fill in the blank with the correct value for each of the interpretations below.

ANSWER CHOICES:



Description

Value

_____% of the variability in price can be explained by the home style.

_____ is the predicted average home price regardless of home style.

For every victorian house we predict a ____ price increase, holding all else constant.

As compared to a lodge home, we predict a victorian home to have a higher price by _____, holding all else constant.

As compared to the average home, we predict the price of a victorian home to be ______ greater, holding all other variables constant.

SOLUTION:

Description

Value

As compared to a lodge home, we predict a victorian home to have a higher price by _____, holding all else constant.

As compared to the average home, we predict the price of a victorian home to be ______ greater, holding all other variables constant.

_____ is the predicted average home price regardless of home style.

For every victorian house we predict a ____ price increase, holding all else constant.

_____% of the variability in price can be explained by the home style.

In order to predict the baseline category in the 1, 0 coding, you use the intercept. In the 1, 0, -1 coding, you need to multiply each categorical coefficient by -1 to get at the missing category. With this in mind, what is the predicted average price for lodges using the 1, 0, -1 coding model?

SOLUTION: 305050