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 webpages 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,
Over the past decades, computers have broadly automated tasks that programmers could describe with clear rules and algorithms. Modern machine learning techniques now allow us to do the same for tasks where describing the precise rules is much harder.
– Jeff Bezos
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 Text Classification
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 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 Text Classification
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. The algorithm makes clusters based on the search term and presents them as results to the user.
Every data point is embedded into the hyperspace and you can visualize them on TensorBoard. The image below is based on a twitter study we did on Reliance Jio, an Indian telecom company.
The data exploration is done to find similar data points based on textual similarity. These similar data points for a cluster of nearest neighbors. The image below shows the nearest neighbors of the tweet “reliance jio prime membership at rs 99 : here’s how to get rs 100 cashback…”.
As you can see, the accompanying tweets are similar to the labeled one. This cluster if one category of similar tweets. Unsupervised classification comes handy while generating insights from textual data. It is highly customizable as no tagging is required. It can operate on any textual data without the need of training and tagging it. Thus, the unsupervised classification is language agnostic.
Upgrading Our Text Classifier
As mentioned earlier, our automated text classification API currently categorize the text into 150 generic categories. This open API is just the tip of the ice berg.
Automated text classification, when you look at it technologically, is a very diverse problem. It has a common outcome of putting text chunks into pre-defined categories, but it becomes a devil when you look into details. Apart from our very generic API, we have solved various problems of text categorization for clients.
There are multiple use cases that ParallelDots’ clients come up with for automated text classification. Some of them want text classified into standard categories like the demo you see on our website/our API, the others want custom classifiers for their own proprietary data, which sometimes they get tagged (so that computers can imitate) and sometimes they don’t. Some of the text classification problems we have solved using advanced Artificial Intelligence are:
- Supervised categorization of sentences for a client’s constantly incoming news/financial data. The deep learning model which does this is trained on a large dataset that was tagged by client’s team. We used state of the art supervised Long Shot Term Memory (LSTM) variants for making a classifier model for them.
- Categorization of user chats for a client who did not have any tagged data using the unsupervised method described above. We used Deep Neural Networks to make autoencoder embedding for the chat to solve this.
- Categorization of long (page length) documents for a client. This is a very different domain from classifying sentences as unlike a sentence, a long document is a mixture of themes. We used Deep Learning based topic models to sort this out.
- We are also working towards technologies where we can provide accurate supervised classification without getting very big datasets tagged. These involve experiments with transfer learning, adversarial training and semi-supervised learning.
We are upgrading our classifier API according to the Interactive Advertising Bureau(IAB). IAB develops industry standards for advertising and media organizations. The IAB standard recommends 360 generic categories for text classification. We will update you with the product launch newsletter post upgradation.
As an AI research group, we are constantly developing cutting-edge technologies to make processes simpler and faster. Text classification is one such technology which has enormous potential in coming future. As more and more information is dumped on the internet, it is up to the intelligent machine algorithms to make analyzing and representing this information easily. The future of machine intelligence is surely exciting, subscribe to our newsletter to get more such information in your inbox.
ParallelDots is an ArtificiaI Intelligence research and Deep Learning startup that provides AI solutions to clients in multiple domains. You can check out some of our text analysis APIs and reach out to us by filling this form here.
