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I am completely new to statistical modelling.I wanted to know what are the feature selection techniques.

Say I have 10 variables but I need to what are actual important one's among them.

I have read about feature selection on internet and came to know few of the techniques:

  1. Correlation
  2. Forward Selection
  3. Backward Elimination

But I am not getting how can I use them. How can a correlation be used in feature selection. How to perform a Forward Selection/Backward Elimination etc.

What models I can use for feature selection. I just want a high level overview of it. When to use what

Some one help me to get started

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Correlation - In this approach we see how the target variable is correlated with the predictors and choose the ones which are highly correlated and ignore the others.

Forward Selection - In this we start with 0 predictors and check the model performance. And then at every stage we add one of the predictor which gives the best model performance.

Backward Selection - In this we start with all the predictors. And then at every stage we remove one of the predictors which gives the better model performance.

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  • In backward selection, forward selection etc do we have to manually add/remove the variables or there are functions which do that automatically Commented Oct 30, 2018 at 12:42
  • Of course we have a library for everything. You can the below link for regression in R with forward and backward selection. sthda.com/english/articles/37-model-selection-essentials-in-r/…
    – Ashok KS
    Commented Oct 30, 2018 at 12:46
  • And for correlation: How do we figure out if there is linear relation between two variables(As far as I know correlation is used with linear relations only) Commented Oct 30, 2018 at 12:50
  • In R a pair plot would show you the correlation between every variable. pair(testData). Correlation is not only for regression. It can be used for classification as well. Also correlation can be used to find any dependency among the predictors.
    – Ashok KS
    Commented Oct 30, 2018 at 12:53

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