What is Relationship Extraction?

What is Relationship Extraction?

Posted on 07/17/2020

Relationship extraction is a revolutionary innovation in the field of natural language processing (NLP). It does way more than automatically inserting metadata to the content about a person, place, or organization. Relationship extraction starts with automation to find people, places, organizations, and entities in an unstructured text. Entity extraction or Named Entity extraction takes place via integration of rules defined as entity lists, regular expressions, and statistical modeling power NER algorithms. 

The power of a machine to understand how entities link and communicate with one another takes the entity extraction to the new level. This kind of information extraction can help in powering knowledge graph generation. It leads to a more comprehensive understanding of data. With this knowledge base, relationship extraction can automatically perform entity recognition and classify the types of relationships between entities. 

For performing relation extraction, it needs to detect and classify the semantic relations within artifacts, usually from text or XML documents. 

Open relationship extraction

One can design relationship extraction algorithms in either open or targeted form. In an open relationship extraction, the algorithm finds and returns the relationship's text snippets along with its arguments. Most of the relationship extraction tools in today's marketplace utilizes open relationship algorithms to perform the task. For instance, the open relationship extraction can link relationship in the following sentence as:

"Barack Obama became the US president in 2009. Obama's timeline of the presidency was from January 2009 to January 2017."

The common entity between two sentences is Obama. However, it might be difficult for an open relationship extraction algorithm to figure out the correct relation between two sentences when "Obama" might not refer to the same object. 

Targeted relationship extraction

In targeted relationship extraction, we pre-train the algorithms for identifying specific relationship types. In an open relationship extraction, it produces semi-structured results and needs some human interpretation. And there is no constraint as it is not limited to a specific set of relationship types. 

Targeted relationship extraction algorithms produce structured information, and downstream applications like the knowledge graph easily digest it. These algorithms extract relations by using a deep conventional neural network for identifying particular actions that connect entities and other related information in a sentence. Target relationship extractors use object linking for connecting every entity mention back to a knowledge base, such as Wikipedia or an associated internal database. The algorithms identify patterns and classify the information. 

For instance, in this sentence, "Aviato was founded by Erlich Bachman. In 2005, Bachman sold the company.", Aviato is taken as a base ID. 

Entity Relationship Extraction for NLP

Natural Language Processing technology is doing a great job of making computers identifying and interpret various human languages. The use of entity-relationship extraction takes place for training the NLP-based AI models to understand the relationships with multiple entities in a text for the analysis of the extracted data. There are various methods for performing entity extraction, from a simple string extraction to automated models. Many experts perform the tasks manually to provide real results for AI-based NLP. 

One can extract features for NLP using supervised and semi-supervised models. 

Supervised Feature Extraction

We can classify verb phrases based on their features. For instance, we can type characteristics like word length, substring, parts of speech tags, word length, capitalization, word shape, etc. There are some advanced feature extractions like bigrams and sequencing modeling (words between two sequences).

Semi-Supervised Seeding

Semi-Supervised seeding works when we know some parts of relationships like Bill Gates and Microsoft, for instance. Like Bill Gates is a person, and Microsoft is an organization. We can apply it to a large dataset with people-organization relationships. 

Here is a research source if you want to know in detail about the neural joint model and biomedical text mining. 

Relation Extraction for Machine Learning 

We can use machine learning to extract relations for finding out connections from an unstructured plain text. One must be careful when retrieving data for creating machine learning models, as it will make predictions using a similar way. It is essential to extract the most relevant datasets for relationship extraction for machine learning. 

The problem with human languages is that it has too much nuisance in it. There can be many spelling errors and grammar mistakes, which can create issues in entity linking task. For making a correct machine learning model, it is essential to figure out methods to calculate accuracy. For instance, Barack is only around 60% of Barack Obama. And we can also try finding out if Barack is married to Michell Obama or not to verify the relationships. 

Relation Extraction Deep Learning

Detecting entity mentions and recognizing its semantic relationships can be challenging. The traditional method usually consists of named entity recognition and relation classification. But, deep learning can be a game-changer and take its accuracy to the next level. Deep neural networks allow machines to learn useful entities and relationships from a sentence without sophisticated manual feature engineering. 

Deep learning models can help companies to find relationships from a massive volume of information to know about their specific products. For instance, one can use deep learning models to find adjectives' connection with each product to know about the company's particular product's popularity from a large set of data. It will prove to be an excellent summarization tool for the company. 

The process of relation extraction deep learning starts with training data sets. Then we move to select relevant features for each word to base our model. The third step is to create and train models via neural networks for correctly predicting and classifying information. Lastly, we link entities for forming the correct bonds. If you want to know more about deep learning in relation extraction, you can go through this content. 

Conclusion

Relationship extraction is a breakthrough technology to help make things easier for developers. The proper use of relationship extraction models can help researchers automate various tasks. And it can also help them identify useful insights from multiple sentence structures. The machines can go through large-scale data and identify relationships for connecting multiple pieces of information. This technology can be an asset for businesses and research institutions if one knows how to utilize it properly.

To learn more about Relationship Extraction, contact the Rosoka team to learn more about how we can help with NLP.

Back to main blog