Challenge #157: An Expert Challenge

[T_Willins]

Wow.  So not ready for the Expert Exam...yet.  I would have spent my entire exam time researching the tools for this.  The difficult part is knowing which predictive tools to use.  Went down a rabbit hole to combine results and calculate Chi-Squared until I revisited the tool documentation for predictive tools and found the Nested Test tool.  I wish I had Alteryx with these tools in college (soooo long ago).

Spoiler

[32bit]

Pardon me if I'm confused, but what does a question like this have to do with a designer certification? Find the answer to that, and you'll know why most people avoided it.

[estherb47]

Cool challenge! I have no idea if my solution is anywhere near correct, but enjoyed getting there nonetheless!

Spoiler

The first approach would normally be to use a Field Summary tool to explore the data. But, since we already know what we want to target, a Summarize tool on H0 is much faster. With just 2 answers, this is probably binary, so I'll model with a Logistic Regression.

Determining the Mean Decrease Gini Coefficient means a Forest model (see the same article that many of us found here)
Variables outlined in the red box below

2 Logistic regressions, one with F_38 and one without. And a Nested Test to compare the two models. Chi-squared is in the nested test

[kelly_gilbert]

Whew, had to spend some quality time with the tool documentation on this one. Statistically, this was out of my depth, however, I was totally surprised to find that I was actually close to the right path. 

Spoiler

I had no idea how (or why) to use the model outputs in a chisq test. TIL about the Nested Test Tool!

[Ladarthure]

Nice challenge, way too hard without the community's help :)

[Garrett]

Glad this one's been retired. 

[ggruccio]

Facing my old nemesis from the expert exam!  I am one of the people who attempted this one.  LOL @CristonS  you won't believe what I did...

Spoiler

So...I knew immediately how to get to the variables with the highest Mean Decrease Gini by using a Random Forest Model.  However when it said compare two models and provide the difference in Chi-Sq I assumed this was also using Random Forest Model for just the 10 variables then removing F38.  Saw no obvious Chi-Sq difference in the output so I googled and believe I found a way to calculate it manually from the confusion matrix.  I would have never figured out that I had to use Logistic Regression and had to peek at the solution to understand it....

[NicoleJohnson]

Community resources to the rescue!!!

Spoiler

Part of me is extremely pleased when the solution to a question has so few tools... the other part of me, which does not entirely understand what I did to get to this answer, is mildly terrified of the fact that this answer required so few tools. :)

Clearly, I now know what I should be doing for the next two months until the Expert exam at Inspire Nashville...

Cheers!

NJ

[JosephSerpis]

Challenge Completed

[PhilipMannering]

Thanks to @patrick_digan for showing me where this variable importance plot was hiding.

My solution attached

Spoiler

workflow