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What is Machine Learning?

You probably use it many times a day without even knowing it. Anytime you want to find out something like “how do I make a sushi roll?” you can do a web search on Google, Bing or Baidu to find out. And that works so well because their machine learning software has figured out how to rank web pages. Or when you upload pictures to Instagram or Snapchat and think to yourself, “I want to tag my friends so they can see their pictures.” Well, these apps can recognize your friends in your pictures and label them as well. That’s also machine learning. Or if you’ve just finished watching a Star Wars movie on the video streaming service and you think “what other similar movies can I watch?” Well the streaming service will likely use machine learning to recommend something that you might like.
Machine learning is the science of getting computers to learn without being explicitly programmed.

Definition

Here’s a definition of what is machine learning that is attributed to Arthur Samuel. He defined machine learning as:
“The field of study that gives computers the ability to learn without being explicitly programmed.”
Samuel’s claim to fame was that back in the 1950s, he wrote a checkers playing program. The amazing thing about this program was that Arthur Samuel himself wasn’t a very good checkers player. What he did was he had programmed the computer to play maybe tens of thousands of games against itself. By watching what positions tend to lead to wins and what positions tend to lead to losses, the checkers playing program learned over time what are good or bad positions. By trying to get to good and avoid bad positions, this program learned to get better and better at playing checkers. Because the computer had the patience to play tens of thousands of games against itself, it was able to get so much checkers playing experience that eventually it became a better checkers player than Samuel himself.

Two Main Types of Machine Learning

The two main types of machine learning are Supervised Learning and Unsupervised Learning. Of these two, supervised learning is the type of machine learning that is used most in many real-world applications and has seen the most rapid advancements and innovation.

Supervised Learning

Learn x to y or input to output mappings with labeled training data

Unsupervised Learning

Find structure or patterns in data without output labels

Supervised Learning

Supervised Machine Learning or more commonly, Supervised Learning (SL), refers to algorithms that learn x to y or input to output mappings.
The key characteristic of supervised learning is that you give your learning algorithm examples to learn from. That includes the right answers, whereby “right answer” means the correct label y for a given input x.
By seeing correct pairs of input x and desired output label y, the learning algorithm eventually learns to take just the input alone without the output label and gives a reasonably accurate prediction or guess of the output.

Unsupervised Learning

In Unsupervised Learning, we’re given data that isn’t associated with any output labels y. Say you’re given data on patients and their tumor size and the patient’s age, but not whether the tumor was benign or malignant.
We’re not asked to diagnose whether the tumor is benign or malignant because we’re not given any labels. Instead, our job is to find some structure or some pattern or just find something interesting in the data.
This is unsupervised learning. We call it unsupervised because we’re not trying to supervise the algorithm to give specific outputs.

Real-World Applications

Machine learning is rapidly making its way into big companies and industrial applications:
Machine learning is already helping to optimize wind turbine power generation, contributing to efforts in combating climate change.
AI is starting to make its way into hospitals to help doctors make accurate diagnoses and improve patient care.
Computer vision is being put into factories to help inspect if something coming off the assembly line has any defects.
Each time you use voice to text on your phone or ask “Hey Siri” or “OK Google” for something, that’s machine learning in action.
When you receive an email titled “Congratulations! You’ve won a million dollars” and your email service flags it as spam - that’s also an application of machine learning.

What’s Next?

Ready to dive deeper into machine learning? Continue with our quickstart guide to get your environment set up and start learning.

Quick Start Guide

Get started with Mindect and set up your learning environment

Jupyter Notebook Setup

Install the most widely used tool for ML practitioners

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