How to prevent common machine learning pitfalls, such as overfitting and underfitting


One of the most crucial branches of artificial intelligence today is machine learning, which enables computers to learn from data and enhance their performance on particular tasks. However there are several dangers that might arise with machine learning, which can reduce its usefulness. Overfitting and underfitting are two of the machine learning mistakes that occur most frequently. We will discuss these problems and how to avoid them in this blog post.

Overfitting: What is it?

When a machine learning model is trained excessively well on a given dataset, it is said to have overfitted and now performs poorly on fresh data. In other words, rather than learning the underlying patterns, the model instead learns the noise in the data. When a model tries to fit the data too closely and is too complex, overfitting might happen. Moreover, it may occur if the training data is insufficient for the intricacy of the model.

How to Avoid Overfitting

Many measures can be taken to avoid overfitting:

1. Increase the dataset's size: Increasing the dataset's size is one of the greatest approaches to avoid overfitting. As a result, the model will be better able to identify patterns in the data rather than merely noise.

2. Use regularisation strategies: Regularization is a strategy for simplifying models. It entails modifying the cost function that the model is attempting to optimise by including a penalty term. With the help of this penalty term, the model will be less likely to overfit by learning too much information from the training set. Utilize cross-validation: Cross-validation is a method for assessing how well a machine learning model is working. It entails repeatedly dividing the data into training and test sets and assessing the model on each split. This makes sure the model is truly learning the fundamental patterns rather than just memorising the training data.

3. Make the model simpler: An overfitting model is more likely if it is very complex. Overfitting risk can be decreased by simplifying the model. This can be accomplished by employing a more straightforward model architecture or by lowering the amount of characteristics.

Underfitting: What is it?

Underfitting is the antithesis of overfitting. It happens when a machine learning model is overly straightforward and fails to recognise the fundamental patterns in the data. In other words, the model doesn't perform well on both the training data and the new data since it isn't complicated enough to suit the data properly.

Ways to Avoid Underfitting

There are numerous methods to avoid underfitting:

1. Make the model more complex: A model that is too simple might not be able to discern the underlying trends in the data. Underfitting can be avoided by making the model more complex. This can be accomplished by utilising a more complicated model architecture or by adding more features.

2. Expand the dataset: A tiny dataset may prevent the model from picking up on the underlying patterns in the data. Underfitting can be avoided by expanding the dataset size.

3. Lessen regularisation: Regularization is employed to prevent overfitting, but too much regularisation can result in underfitting. It could be required to weaken the regularisation if a model is underfitting.

4. Employ a different model: It could be required to adopt an alternative model architecture or methodology if a model continually underfits the data.


In machine learning, overfitting and underfitting are frequent issues. Underfitting happens when a model is too basic and is unable to capture the underlying patterns in the data, whereas overfitting happens when a model is too specific to a given dataset. It is crucial to employ strategies like expanding the dataset, applying regularisation techniques, cross-validation, simplifying or complicating the model, and adopting a new model to avoid these errors.

A balance must be struck in order to avoid both overfitting and underfitting. We want our models to be sufficiently complex to capture the underlying patterns in the data, but we also want to guard against the model becoming too accustomed to the training set and underperforming on novel data. Thus, it is crucial. to monitor the model's performance and make necessary changes to achieve the ideal ratio of complexity to generalisation.

Finally, overfitting and underfitting are frequent machine learning problems that might reduce the efficacy of our models. We may steer clear of these traps and create accurate, generalizable models by employing the methods described in this blog article.