# What Is Log Loss in Machine Learning?

Machine learning is exciting, as it not only enables artificial intelligence but shows promise to reshape the world around us. Since the digital landscape is slowly getting integrated more and more into our everyday lives – machine learning solutions continually sophisticate it, changing the way we interact with everything around us.

Evaluating the machine learning model is one of the defining traits of machine learning as a whole, as it balances the actual implementation of the technology and the mathematical algorithms that enable it.

While this all sounds reasonable enough, everyone who deals with machine learning will have to consider an error. The best way to determine the algorithm’s accuracy is through error metrics, the most popular of which is log loss.

## What Is Log Loss?

Log loss is one of the most popular measurements of error in applied machine learning. Errors and learning initiative failures play an essential role in the machine learning process, as discovering them and minimizing them ultimately maximizes the process’s accuracy.

Log loss is measured in units, and depending on the scope and type of case and problem, the different values might be better or worse.

Log loss is an essential metric that defines the numerical value bifurcation between the presumed probability label and the true one, expressing it in values between zero and one.

Generally, multiclass problems have a far greater tolerance for log loss than centralized and focused cases. While the ideal log loss is zero, the minimum acceptable log loss value will vary from case to case.

It’s a global metric that dictates the performance of your model in a particular case. Many other metrics are better suited for analyzing errors in specific cases, but log loss is a useful and straightforward way to compare two models.

**How is log loss presented? **

Log loss is presented numerically in values between one and zero. That is because the accuracy or likelihood is shown in these same values, and the log loss error margin needs to be in between. If the log loss value exceeds more than 0.70 in an unbiased, broad case, it’s not that much of an issue. If it exceeds the same value in a clear, biased, and centralized case, it’s quite the issue.

The likelihood is determined by the model and the case itself, meaning log loss can have the same value but two drastically different meanings, based on the unique case – making it a less than ideal metric for measuring error.

## What Does Log Loss Apply to?

Log loss applies to the prediction process in machine learning and applies almost strictly to the probabilities. The lower the log loss, the more accurate predictions your AI will make, meaning its overall accuracy and functionality will rise.

To put this in layman’s terms, the smaller the log loss value, the better the machine learning process, as the likelihood and prediction errors decrease.

This function is mostly used to train binary classifiers, relatively simple tasks with two accurate and inaccurate labels.

**What are binary classifiers? **

Binary classifiers are classification systems that work within the binary system, meaning their sole purpose is to define whether something is positive or negative. They have vast applications and are one of the most incorporated pieces of software around.

A good example of binary classifiers would be spam detection software in emails. A binary classifier’s job is to define whether the incoming email is spam or not, and logarithmic loss muddles its judgment.

That means that the higher the logarithmic loss, the higher the binary classifier’s chance of making a mistake and pushing away a non-spam email or letting a spam email through.

**What about multiclass classification?**

While log loss has applications in multiclass classification, it’s not the recommended metric for the job. Multiclass classification is a far more complex task than simple binary classification, making log loss an inaccurate metric, as it’s completely label-dependent.

## How Is Log Loss Calculated?

Since log loss is a mathematical function, it has a clear definition. But before we get to the definition, we’ll have to note that for log loss to be accurate, the user must define each class’s probability before applying the function.

The application of probability to each class that goes into the log loss equation increases the overall function’s accuracy. Defining log loss is as simple as locating the corrected probabilities, logging all of them, and taking the negative average defined by logging the corrected probabilities.

After this is finished, we can apply the formula to calculate log loss.

## Why is Log Loss significant?

While complicated, log loss is an essential metric used for applied machine learning and is widely used for binary classifiers. Without log loss, the artificial intelligence that enables many of our day-to-day activities wouldn’t make proper decisions, making it less than ideal for commercial applications.

The way the data is classified, established, and finally set in motion for machine learning defines its success rate, so even with the accurate data, the distributing method matters significantly.

Data processing methods can simplify or streamline the classification process, minimizing log loss and making integration and deployment as seamless as possible.

## Final Thoughts

While log loss is one of the best ways to manage and maximize accuracy, the way the final data is deployed is also essential. Through services such as Pandio, the whole process is streamlined to near perfection.

Pandio is a top-of-the-line distributed messaging system that’s specifically designed for machine learning and AI, allowing you to put all of that effort from determining and minimizing log loss to good use.

Pandio operates on the Apache Pulsar platform, which allows you to seamlessly connect complex systems in applied machine learning, further simplifying and speeding up the whole process.