Preprocessing methods

Sources:

https://towardsdatascience.com/all-about-categorical-variable-encoding-305f3361fd02

One Hot Encoding

(-) n labels will create 2^n variables.
(+) interpretable

Hashing Encoding

(+) considerably reduce the number of variables
(-) interpretable, loose information

Classic Hash

(-) collisions with unrelated labels

Local Sensitive Hashing (LSH)

(+/-) close elements are considered similar

Target Encoding (Level Encoding)

(+) great for high cardinality of categorical variables