Search the courses, subjects, tracks, games and features, or jump straight to a page.
Learn it your way
A short class with Sarah and her students. The other ways are under More.
Sign up free to listen. Transcripts are free to read.
Today, we're going to talk about two important concepts in Machine Learning: features and target variables. Can anyone tell me what we mean by features?
Are features the input data that we use to train the model?
Exactly right! Features, often represented as 'X', are the input variables such as age or hours studied. Now, what about the target variable?
I think the target is the output we want to predict, like scores or prices?
Correct! The target, often represented as 'y', is the outcome we desire to predict. Remember this: Features are what we provide to the model, and the target is what we want to know!
Can we have more than one feature?
Absolutely! We can use multiple features to improve predictions. Just think of it as piecing together a puzzle.
To summarize, features are the inputs, and the target is the output. This dynamic is foundational in any ML model.
Now let's dive into overfitting and underfitting. Both are crucial in understanding how your model behaves. Can anyone define overfitting?
Isn't it when a model learns the training data too well and fails on new data?
That's a great understanding! Overfitting means the model is doing very well on the training set but poorly on new, unseen data. What do you think underfitting means?
I think it's when the model is too simple and doesn’t learn enough from the data.
Exactly! Underfitting occurs when the model is too simplistic and cannot capture the underlying patterns, leading to poor performance on both the training and test datasets. Remember: We want to find the right balance!
How do we know if our model is overfitting or underfitting?
That's where evaluation metrics come into play, which we'll cover later. But in essence, we evaluate performance on the test set to gauge this balance.
To summarize, overfitting is learning too much noise and underfitting is learning too little from the data.
Finally, let’s look at the train/test split. Why do you think it's essential to split our data?
So we can test the model's performance accurately?
Exactly! The train/test split helps ensure that we evaluate the model on unseen data, which is crucial for understanding its real-world performance.
How do we usually go about splitting the data?
Commonly, we use an 80/20 split where 80% of the data is used for training the model, and 20% is reserved for testing. This gives us a fair idea of how well the model will perform on new data.
Do all Machine Learning models need the train/test split?
Yes! It’s a best practice for most models to prevent overfitting. Remember: a good model learns to generalize well to unseen data.
To summarize, the train/test split is crucial for evaluating model performance and mitigating overfitting.
The input variables used to make predictions.
The output variable that is predicted by the model.
Occurs when a model learns too much from the training data and performs poorly on new data.
Happens when a model is too simplistic and fails to capture patterns.
The process of dividing the dataset to evaluate the model's performance on unseen data.
Features predict the scores, Targets we adore, Never overfit, Or you'll be in a fit!
Imagine a chef (the model) who learns only from a few special recipes (training data). If he tries to cook only those, he impresses guests only sometimes (overfitting). But if he learns to cook without those and embraces all kinds of ingredients (features), he delights everyone!
Remember F.O.U.T: Features, Output, Underfitting, and Training split - essential concepts in ML!
Use the acronym FOTUS: F for Features, O for Output (target), T for Train/Test Split, U for Underfitting, S for Supervised learning!
Term
Features
Click to flip
Term
Target
Click to flip
Term
Overfitting
Click to flip
Term
Underfitting
Click to flip
Term
Train/Test Split
Click to flip
Input variables that are used by the model to make predictions (e.g., age, hours studied).
The output variable that the model aims to predict (e.g., salary, exam score).
A modeling error that occurs when the model learns the training data too well, failing to perform well on new, unseen data.
A condition where a model is too simple to capture underlying patterns in the training data.
The practice of dividing data into two subsets: one for training the model and another for testing its performance.
This section covers critical terminology related to Machine Learning that is essential for understanding its concepts.
The section introduces crucial Machine Learning terms such as features, target, overfitting, and underfitting. Understanding these terms is vital for discussing and applying Machine Learning effectively.
In this section, we examine the terminology pivotal to Machine Learning (ML). Understanding these terms will lay the groundwork for discussing ML methodologies and models. Key terms include: