https://communities.sas.com/t5/SAS-Academy-for-Data-Science/Data-imputation-before-or-after-variable-transformation/m-p/650509#M817 <P>Re: Predictive Modeling Using Logistic Regression</P> <P>At page 3-59 of the course text, variable transformation is suggested as a way of accounting for nonlinear relationship between input and output. However, the way the topics (and related SAS logic steps) are presented in the course, imputation of missing values is done in an earlier step (as part of the data preparation stage). On the other hand, throughout course "Applied Analytics Using SAS Enterprise Miner" it is emphasized that data imputation should be done after transforming variables (see page 4-53 of the course text): which way is the most appropriate or is either approach valid?</P> <P><FONT color="#0000FF"><STRONG>My response:</STRONG></FONT></P> <P><FONT color="#0000FF"><STRONG>The following are best practice steps related to fitting regression models:</STRONG></FONT></P> <UL> <LI><FONT color="#0000FF"><STRONG>Out of the following three pre-processing steps (re_coding categorical levels, interval input transformation and missing value imputation) before regression modeling, the missing value imputation step&nbsp; is the most significant step. That is why it is introduced first in the AAEM training in Ch4.</STRONG></FONT></LI> <LI><FONT color="#0000FF"><STRONG>Also we recommend that the missing value imputation step must be the last step before fitting the regression&nbsp;model</STRONG></FONT></LI> </UL> Mon, 25 May 2020 19:22:51 GMT gcjfernandez 2020-05-25T19:22:51Z https://communities.sas.com/t5/SAS-Academy-for-Data-Science/Data-imputation-before-or-after-variable-transformation/m-p/650204#M816 <P>Re: Predictive Modeling Using Logistic Regression</P> <P>At page 3-59 of the course text, variable transformation is suggested as a way of accounting for nonlinear relationship between input and output. However, the way the topics (and related SAS logic steps) are presented in the course, imputation of missing values is done in an earlier step (as part of the data preparation stage). On the other hand, throughout course "Applied Analytics Using SAS Enterprise Miner" it is emphasized that data imputation should be done after transforming variables (see page 4-53 of the course text): which way is the most appropriate or is either approach valid?</P> Sun, 24 May 2020 18:39:48 GMT https://communities.sas.com/t5/SAS-Academy-for-Data-Science/Data-imputation-before-or-after-variable-transformation/m-p/650204#M816 pvareschi 2020-05-24T18:39:48Z https://communities.sas.com/t5/SAS-Academy-for-Data-Science/Data-imputation-before-or-after-variable-transformation/m-p/650509#M817 <P>Re: Predictive Modeling Using Logistic Regression</P> <P>At page 3-59 of the course text, variable transformation is suggested as a way of accounting for nonlinear relationship between input and output. However, the way the topics (and related SAS logic steps) are presented in the course, imputation of missing values is done in an earlier step (as part of the data preparation stage). On the other hand, throughout course "Applied Analytics Using SAS Enterprise Miner" it is emphasized that data imputation should be done after transforming variables (see page 4-53 of the course text): which way is the most appropriate or is either approach valid?</P> <P><FONT color="#0000FF"><STRONG>My response:</STRONG></FONT></P> <P><FONT color="#0000FF"><STRONG>The following are best practice steps related to fitting regression models:</STRONG></FONT></P> <UL> <LI><FONT color="#0000FF"><STRONG>Out of the following three pre-processing steps (re_coding categorical levels, interval input transformation and missing value imputation) before regression modeling, the missing value imputation step&nbsp; is the most significant step. That is why it is introduced first in the AAEM training in Ch4.</STRONG></FONT></LI> <LI><FONT color="#0000FF"><STRONG>Also we recommend that the missing value imputation step must be the last step before fitting the regression&nbsp;model</STRONG></FONT></LI> </UL> Mon, 25 May 2020 19:22:51 GMT https://communities.sas.com/t5/SAS-Academy-for-Data-Science/Data-imputation-before-or-after-variable-transformation/m-p/650509#M817 gcjfernandez 2020-05-25T19:22:51Z