Supervised learning:
A supervised learning algorithm analyzes the training data and produces an inferred function, which can be used for mapping new examples.
- We provide training data and we know correct output for a certain input
- We know relation between input and output
Categories of problem:
Regression: Predict results within a continuous output => map input variables to some continuous function.
Example:
Given a picture of a person, predict his age
Classification: Predict results in a discrete output => map input variables into discrete categories
Example:
Is this tumer cancerous?
Unsupervised learning:
Unsupervised learning learns from test data that has not been labeled, classified or categorized. Unsupervised learning identifies commonalities in the data and reacts based on the presence or absence of such commonalities in each new piece of data.
We can derive this structure by clustering the data based on relationships among the variables in the data.
There is no feedback based on the prediction results.
Categories of problem:
Clustering: is the task of grouping a set of objects in such a way that objects in the same group (called a cluster) are more similar (in some sense) to each other than to those in other groups (clusters)
Example:
Take a collection of 1,000,000 different genes, and find a way to automatically group these genes into groups that are somehow similar or related by different variables, such as lifespan, location, roles, and so on.
Popular use cases are listed here.
Difference between classification and clustering in data mining?
References:
Supervised_learning
Unsupervised_learning
machine-learning from coursera
towardsdatascience
