Uploaded September 2018 | Updated September 2026, 1 week ago
Bias and Variance are two fundamental concepts for Machine Learning, and their intuition is just a little different from what you might have learned in your statistics class. Here I go through two examples that make these concepts super easy to understand.
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0:00 Awesome song and introduction
0:29 The data and the "true" model
1:23 Splitting the data into training and testing sets
1:40 Least Regression fit to the training data
2:16 Definition of Bias
2:33 Squiggly Line fit to the training data
3:40 Model performance with the testing dataset
4:06 Definition of Variance
5:10 Definition of Overfit
Correction:
4:06 I say that the difference in fits between the training dataset and the testing dataset is called Variance. However, I should have said that the difference is a _consequence_ of variance. Technically, variance refers to the amount by which the predictions would change if we fit the model to a different training data set.
#statquest #biasvariance #ML
Bias and Variance are two fundamental concepts for Machine Learning, and their intuition is just a little different from what you might have learned in your statistics class. Here I go through two examples that make these concepts super easy to understand.
For a complete index of all the StatQuest videos, check out:
statquest.org/video-index
If you'd like to support StatQuest, please consider...
Patreon: patreon.com/statquest
...or...
YouTube Membership: youtube.com/channel/UCtYLUTtgS3k1Fg4y5tAhLbw/join
...buying one of my books, a study guide, a t-shirt or hoodie, or a song from the StatQuest store...
statquest.org/statquest-store
...or just donating to StatQuest!
paypal.me/statquest
Lastly, if you want to keep up with me as I research and create new StatQuests, follow me on twitter:
twitter.com/joshuastarmer
0:00 Awesome song and introduction
0:29 The data and the "true" model
1:23 Splitting the data into training and testing sets
1:40 Least Regression fit to the training data
2:16 Definition of Bias
2:33 Squiggly Line fit to the training data
3:40 Model performance with the testing dataset
4:06 Definition of Variance
5:10 Definition of Overfit
Correction:
4:06 I say that the difference in fits between the training dataset and the testing dataset is called Variance. However, I should have said that the difference is a _consequence_ of variance. Technically, variance refers to the amount by which the predictions would change if we fit the model to a different training data set.
#statquest #biasvariance #ML
