Automated Text Classification Using Machine Learning

Digitization has changed the way we process and analyze information. There is an exponential increase in online availability of information. From web pages to emails, science journals, e-books, learning content, news and social media are all full of textual data. The idea is to create, analyze and report information fast. This is when automated text classification steps up.
Text classification is a smart classification of text into categories. And, using machine learning to automate these tasks, just makes the whole process super-fast and efficient. Artificial Intelligence and Machine learning are arguably the most beneficial technologies to have gained momentum in recent times. They are finding applications everywhere. As Jeff Bezos said in his annual shareholder’s letter,
Talking particularly about automated text classification, we have already written about the technology behind it and its applications. We are now updating our text classifier. In this post, we talk about the technology, applications, customization, and segmentation related to our automated text classification API.
Intent, emotion and sentiment analysis of textual data are some of the most important parts of text classification. These use cases have made significant buzz among the machine intelligence enthusiasts. We have developed separate classifiers for each such category as their study is a huge topic in itself. Text classifier can operate on a variety of textual datasets. You can train the classifier with tagged data or operate on the raw unstructured text as well. Both of these categories have numerous application of themselves.
Supervised classification of text is done when you have defined the classification categories. It works on training and testing principle. We feed labeled data to the machine learning algorithm to work on. The algorithm is trained on the labeled dataset and gives the desired output(the pre-defined categories). During the testing phase, the algorithm is fed with unobserved data and classifies them into categories based on the training phase.
Spam filtering of emails is one example of supervised classification. The incoming email is automatically categorized based on its content. Language detection, intent, emotion and sentiment analysis are all based on supervised systems. It can operate for special use cases such as identifying emergency situation by analyzing millions of online information. It is a needle in the haystack problem. We proposed a smart public transportation system to identify such situations. To identify emergency situation among millions of online conversation, the classifier has to be trained with high accuracy. It needs special loss functions, sampling at training time and methods like building a stack of multiple classifiers each refining the results of previous one to solve this problem.
Supervised classification is basically asking computers to imitate humans. The algorithms are given a set of tagged/categorized text (also called train set) based on which they generate AI models, these models when further given the new untagged text, can automatically classify them. Several of our APIs, are developed with supervised systems. The text classifier is currently trained for a set of generic 150 categories.
Unsupervised classification is done without providing external information. Here the algorithms try to discover natural structure in data. Please note that natural structure might not be exactly what humans think of as logical division. The algorithm looks for similar patterns and structures in the data points and groups them into clusters. The classification of the data is done based on the clusters formed. Take web search for an example.


