# feature engineering and selection featuresunderstand your data better data and datasets features models revisiting the machine learning pipeline feature extraction and engineering what is feature engineering? why feature engineering? how do you engineer features? feature engineering on numeric data raw measures binarization rounding interactions binning statistical transformations feature engineering on categorical data transforming nominal features transforming ordinal features encoding categorical features feature engineering on text data text pre-processing bag of words model bag of -grams model tf-idf model document similarity topic models word embeddings ix