# Are Machine Learning models probabilistic models? [closed]

In terms of Machine Learning models, as far as I know, there are two kinds of models in Machine Learning. One kind are discriminative models and the other kind are generative models. But I wonder if those two kinds of Machine Learning models are probabilistic models.

• It seems like the answer to this question must depend on which machine learning model in particular we are considering and how you define a probabilistic model. This question reminds me of the discussion around stats.stackexchange.com/questions/127042/…
– Sycorax
Jan 3, 2020 at 16:25

Some, but not all, of the machine learning models, are probabilistic models. There are machine learning models that are probabilistic by design, such as Naive Bayes. There are also ones that are not probabilistic, like SVM, random forest, or $$k$$-NN, because they were not designed in terms of thinking of random variables and probability distributions.
Being a probabilistic model is a "nice to have" feature for machine learning model, because it makes easier for us to evaluate the uncertainties related to the predictions returned by the model. It is not "obligatory", because in machine learning we usually worry only about making accurate predictions (rather then inference), and in many cases the well established tools for assessing their performance, like cross-validation, are enough for this task. For example, $$k$$-NN classifies cases based on their similarities to other samples in the training data, and this both works and is intuitively appealing way of making classifications, there is no need to defining it in probabilistic terms.