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I have created several Partial Dependence Plots (PDP) for some of the top variables in my RF model. Overall, the plots seem to make sense; however, for the 'Bog" class, the probability for all variables analyzed goes up to around 0.9 probability, while for the other variables, the probability is significantly less (e.g. 0.02).

I understand that the probability will change depending on the class, and a predictor variable may have more importance in one class than another. However, the high probability for all bog classes has me questioning the data. I would appreciate any feedback and ideas on troubleshooting approaches (if necessary). enter image description here enter image description here enter image description here

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  • $\begingroup$ If you exclude that class from your RF, and then re-train it, how does the validation score change? $\endgroup$ Commented Feb 13 at 15:30
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    $\begingroup$ @EngrStudent, it dropped like 0.3% so is around 92% OA. $\endgroup$ Commented Feb 13 at 16:00
  • $\begingroup$ This suggests that the overall learning is not compromised by that label. 0.3% of 92% can be run-to-run training variation. If you reran it 100 times with different seeds, you might easily get that. I was initially thinking you might have something that allows the learner to "index" (basically create a false-hash) so it looks like it has near perfect learning, but it is just memorizing and has terrible generalization. $\endgroup$ Commented Feb 14 at 4:21
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    $\begingroup$ I only ran the model twice. I found out what I did wrong. I was having issues making PDPs for each class, so I created subsets of my data per class from the rf model and then made the PDPs. This explains why I had funky results. I rewrote my script and used the which,class argument and got the results I desired and what makes sense. Thanks for your input! $\endgroup$ Commented Feb 15 at 2:46
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    $\begingroup$ So write up a clean if brief and effective answer for posterity. $\endgroup$ Commented Feb 15 at 14:13

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I only ran the model twice. I found out what I did wrong. I was having issues making PDPs for each class, so I created subsets of my data per class from the rf model and then made the PDPs. This explains why I had funky results. I rewrote my script and used the which,class argument and got the results I desired and what makes sense.[]

-- John Gallop

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