Every time we hear a word or read a text, we have the natural ability to identify and categorize the word into people, place, location, values, and more. Humans can quickly recognize a word, categorize it and understand the context. For example, when you hear the word ‘Steve Jobs,’ you can immediately think of at least three to four attributes and segregate the entity into categories,
- Person: Steve Jobs
- Company: Apple
- Location: California
Since computers don’t have this natural ability, they require our help to identify words or text and categorize them. It is where Named Entity Recognition (NER) comes into play.
Let’s get a brief understanding of NER and its relation to NLP.
What is Named Entity Recognition?
Named Entity Recognition is a part of Natural Language Processing. The primary objective of NER is to process structured and unstructured data and classify these named entities into predefined categories. Some common categories include name, location, company, time, monetary values, events, and more.
In a nutshell, NER deals with:
- Named entity recognition/detection – Identifying a word or series of words in a document.
- Named entity classification – Classifying every detected entity into predefined categories.
But how is NER related to NLP?
Natural Language processing helps develop intelligent machines capable of extracting meaning from speech and text. Machine Learning helps these intelligent systems continue learning by training on large amounts of natural language data sets.
Generally, NLP consists of three major categories:
- Understanding the structure and rules of the language – Syntax
- Deriving meaning of words, text, and speech and identifying their relationships – Semantics
- Identifying and recognizing spoken words and transforming them into text – Speech
NER helps in the semantic part of NLP, extracting the meaning of words, identifying and locating them based on their relationships.
A Deep Dive into Common NER Entity Types
Named Entity Recognition models categorize entities into various predefined types. Understanding these types is crucial for leveraging NER effectively. Here’s a closer look at some of the most common ones:
- Person (PER): Identifies individuals’ names, including first, middle, and last names, titles, and honorifics. Example: Nelson Mandela, Dr. Jane Doe
- Organization (ORG): Recognizes companies, institutions, government agencies, and other organized groups. Example: Google, World Health Organization, United Nations
- Location (LOC): Detects geographical locations, including countries, cities, states, addresses, and landmarks. Example: London, Mount Everest, Times Square
- Date (DATE): Extracts dates in various formats. Example: January 1, 2024, 2024-01-01
- Time (TIME): Identifies time expressions. Example: 3:00 PM, 15:00
- Quantity (QUANTITY): Recognizes numerical quantities and units of measurement. Example: 10 kilograms, 2 liters
- Percentage (PERCENT): Detects percentages. Example: 50%, 0.5
- Money (MONEY): Extracts monetary values and currencies. Example: $100, €50
- Other (MISC): A catch-all category for entities that don’t fit into the other types. Example: Nobel Prize, iPhone 15″
Examples of Named Entity Recognition
Some of the common examples of a predetermined entity categorization are:
Apple: is labeled as ORG (Organization) and highlighted in red. Today: is labeled as DATE and highlighted in pink. Second: is labeled as QUANTITY and highlighted in green. iPhone SE: is labeled as COMM (Commercial product) and highlighted in blue. 4.7-inch: is labeled as QUANTITY and highlighted in green.
Ambiguity in Named Entity Recognition
The category a term belongs to is intuitively quite clear for human beings. However, that’s not the case with computers – they encounter classification problems. For example:
Manchester City (Organization) won the Premier League Trophy whereas in the following sentence the organization is used differently. Manchester City (Location) was a Textile and industrial Powerhouse.
Your NER model needs training data to conduct accurate entity extraction and classification. If you are training your model on Shakespearean English, needless to say, it won’t be able to decipher Instagram.
Different NER Approaches
The primary goal of a NER model is to label entities in text documents and categorize them. The following three approaches are generally used for this purpose. However, you can choose to combine one or more methods as well. The different approaches to creating NER systems are:
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Dictionary-based systems
The dictionary-based system is perhaps the most simple and fundamental NER approach. It will use a dictionary with many words, synonyms, and vocabulary collection. The system will check whether a particular entity present in the text is also available in the vocabulary. By using a string-matching algorithm, a cross-checking of entities is performed.
One drawback of using this approach is there is a need for constantly upgrading the vocabulary dataset for the effective functioning of the NER model.
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Rule-based systems
In this approach, information is extracted based on a set of pre-set rules. There are two primary sets of rules used,
Pattern-based rules – As the name suggests, a pattern-based rule follows a morphological pattern or string of words used in the document.
Context-based rules – Context-based rules depend on the meaning or the context of the word in the document.
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Machine learning-based systems
In Machine learning-based systems, statistical modeling is used to detect entities. A feature-based representation of the text document is used in this approach. You can overcome several drawbacks of the first two approaches since the model can recognize entity types despite slight variations in their spellings.
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Deep learning
Deep learning methods for NER leverage the power of neural networks like RNNs and transformers to understand long-term text dependencies. The key benefit of using these methods is they are well-suited for large-scale NER tasks with abundant training data.
Furthermore, they can learn complex patterns and features from the data itself, eliminating the need for manual training. But there’s a catch. These methods require a hefty amount of computational power for training and deployment.
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Hybrid Methods
These methods combine approaches like rule-based, statistical, and machine learning to extract named entities. The goal is to combine the strengths of each method while minimising their weaknesses. The best part of using hybrid methods is the flexibility you get by merging multiple techniques by which you can extract entities from diverse data sources.
However, there’s a possibility that these methods may end up getting much more complex than the single-approach methods as when you merge multiple approaches, the workflow may get confusing.
Use Cases for Named Entity Recognition (NER)?
Unveiling the Versatility of Named Entity Recognition (NER):
- Chatbots: Aids chatbots like GPT in understanding user queries by identifying key entities.
- Customer Support: Categorizes feedback by product, accelerating response time.
- Finance: Extracts crucial data from financial reports,for trend analysis and risk assessment.
- Healthcare: It pulls essential information from clinical records, promoting quicker data analysis.
- HR: Streamlines recruitment by summarizing applicant profiles & channeling feedback.
- News Providers: Categorizes content into relevant information, speeding up reporting.
- Recommendation Engines: Companies like Netflix employ NER to personalize recommendations based on user behavior.
- Search Engines: By categorizing web content, NER enhances search result accuracy.
- Sentiment Analysis: Extracts brand mentions from reviews, fueling sentiment analysis tools.
Who Uses Named Entity Recognition (NER)?
NER (Named Entity Recognition) being one of the powerful natural language processing (NLP) techniques has made its way to various industries and domains. Here are some examples:
- Search engines: NER is a core component of modern-day search engines such as Google and Bing. It is used to identify and categorise entities from web pages and search queries to provide more relevant search results. For example, with the help of NER, the search engine can differentiate between “Apple” the company vs. “apple” the fruit based on context.
- Chatbots: Chatbots and AI assistants can use NER to understand key entities from user queries. By doing so, chatbots can provide more precise responses. For example, if you ask “Find Italian restaurants near Central Park” the chatbot will understand “Italian” as the cuisine type, “restaurants” as the place, and “Central Park” as the location.
- Investigative Journalism: The International Consortium of Investigative Journalists (ICIJ), a renowned media organization used NER to analyse the Panama Papers, a massive leak of 11.5 million financial and legal documents. In this case, NER was used to automatically identify people, organizations, and locations across millions of unstructured documents, uncovering hidden networks of offshore tax evasion.
- Bioinformatics: In the field of Bioinformatics, NER is used to extract key entities such as genes, proteins, drugs, and diseases from biomedical research papers and clinical trial reports. Such data helps in fastening the process of drug discovery.
- Social Media Monitoring: Brands over social media use NER to track the overall metrics of their ad campaigns and how their competitors are doing. For example, there’s an airline that uses NER to analyse tweets mentioning their brand. It detects negative commentary around entities like “lost luggage” at a particular airport so that they can resolve the problem as fast as possible.
- Contextual Advertising: Advertisement platforms use NER to extract key entities from web pages to display more relevant ads alongside the content eventually improving ad targeting and click-through rates. For example, if NER detects “Hawaii”, “hotels”, and “beaches” on a travel blog, the ad platform will show deals for Hawaiian resorts rather than generic hotel chains.
- Recruiting and Resume Screening: You can instruct NER to find you the exact required skills and qualifications based on the applicant’s skill set, experience and background. For example, a recruitment agency can use NER to match candidates automatically.
Applications of NER
NER has several use cases in many fields related to Natural Language Processing and creating training datasets for machine learning and deep learning solutions. Some of the applications are:
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Customer Support
A NER system can easily spot relevant customer complaints, queries, and feedback based on crucial information such as product names, specifications, branch locations, and more. The complaint or feedback is aptly classified and diverted to the correct department by filtering priority keywords.
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Efficient Human Resources
NER helps Human Resource teams improve their hiring process and reduce the timelines by quickly summarizing applicants’ resumes. The NER tools can scan the resume and extract relevant information – name, age, address, qualification, college, and so forth.
Additionally, the HR department can also use NER tools to streamline the internal workflows by filtering employee complaints and forwarding them to the concerned departmental heads.
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Content Classification
Content classification is a humongous task for news providers. Classifying the content into different categories makes it easier to discover, gain insights, identify trends, and understand the subjects. A Named Entity Recognition tool can come in handy for news providers. It can scan many articles, identify priority keywords, and extract information based on the persons, organization, location, and more.
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Optimizing Search Engines
NER helps in simplifying and improving the speed and relevance of search results. Instead of running the search query for thousands of articles, a NER model can run the query once and save the results. So, based on the tags in the search query, the articles associated with the query can be quickly picked up.
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Accurate Content recommendation
Several modern applications depend on NER tools to deliver an optimized and customized customer experience. For example, Netflix provides personalized recommendations based on user’s search and view history using named entity recognition.
Named Entity Recognition makes your machine learning models more efficient and reliable. However, you need quality training datasets for your models to work at their optimum level and achieve intended goals. All you need is an experienced service partner who can provide you with quality datasets ready to use. If that’s the case, Shaip is your best bet yet. Reach out to us for comprehensive NER datasets to help you develop efficient and advanced ML solutions for your AI models.
[Also Read: What is NLP? How it Works, Benefits, Challenges, Examples
How Does Named-entity Recognition Work?
Delving into the realm of Named Entity Recognition (NER) unveils a systematic journey comprising several phases:
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Tokenization
Initially, the textual data is dissected into smaller units, termed tokens, which can range from words to sentences. For example, the statement “Barack Obama was the president of the USA” is segmented into tokens like “Barack”, “Obama”, “was”, “the”, “president”, “of”, “the”, and “USA”.
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Entity Detection
Utilizing a concoction of linguistic guidelines and statistical methodologies, potential named entities are spotlighted. Recognizing patterns like capitalization in names (“Barack Obama”) or distinct formats (like dates) is crucial in this stage.
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Entity Classification
Post detection, entities are sorted into predefined categories such as “Person”, “Organization”, or “Location”. Machine learning models, nurtured on labeled datasets, often drive this classification. Here, “Barack Obama” is tagged as a “Person” and “USA” as a “Location”.
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Contextual Evaluation
The prowess of NER systems is often amplified by evaluating the surrounding context. For instance, in the phrase “Washington witnessed a historic event”, the context helps discern “Washington” as a location rather than a person’s name.
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Post-Evaluation Refinement
Following the initial identification and classification, a post-evaluation refinement may ensue to hone the results. This stage could tackle ambiguities, fuse multi-token entities, or utilize knowledge bases to augment the entity data.
This delineated approach not only demystifies the core of NER but also optimizes the content for search engines, enhancing the visibility of the intricate process that NER embodies.
NER Tools and Libraries Comparison:
Several powerful tools and libraries facilitate NER implementation. Here’s a comparison of some popular options:
Tool/Library | Description | Strengths | Weaknesses |
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spaCy | A fast and efficient NLP library in Python. | Excellent performance, easy to use, pre-trained models available. | Limited support for languages other than English. |
NLTK | A comprehensive NLP library in Python. | Wide range of functionalities, good for educational purposes. | Can be slower than spaCy. |
Stanford CoreNLP | A Java-based NLP toolkit. | Highly accurate, supports multiple languages. | Requires more computational resources. |
OpenNLP | A machine learning-based toolkit for NLP. | Supports multiple languages, customizable. | Can be complex to set up. |
NER Benefits & Challenges?
Benefits:
- Information Extraction: NER identifies key data, aiding information retrieval.
- Content Organization: It helps categorize content, useful for databases and search engines.
- Enhanced User Experience: NER refines search outcomes and personalizes recommendations.
- Insightful Analysis: It facilitates sentiment analysis and trend detection.
- Automated Workflow: NER promotes automation, saving time and resources.
Limitations / Challenges:
- Ambiguity Resolution: Struggles with distinguishing similar entities like “Amazon” as a river or company.
- Domain-Specific Adaptation: Resource-intensive across diverse domains.
- Language Variations: Effectiveness varies due to slang and regional differences.
- Scarcity of Labeled Data: Needs large labeled datasets for training.
- Handling Unstructured Data: Requires advanced techniques.
- Performance Measurement: Accurate evaluation is complex.
- Real-Time Processing: Balancing speed with accuracy is challenging.
- Context Dependency: Accuracy relies on understanding surrounding text nuances.
- Data Sparsity: Requires substantial labeled datasets, especially for niche areas.
The future of NER
While Named Entity Recognition (NER) is a well-established field, there is still much work to be done. One promising area that we can consider is deep learning techniques including transformers and pre-trained language models, so the performance of NER can be improved further.
Another exciting idea is building custom NER systems for different professions, like doctors or lawyers. As different industries have their own identity types and patterns, creating NER systems in these specific contexts can provide more precise and relevant results.
Furthermore, multilingual and cross-lingual NER is also an area of growing faster than ever. With the increasing globalization of business, we need to develop NER systems that can handle diverse linguistic structures and scripts.
Conclusion
Named Entity Recognition (NER) is a powerful NLP technique that identifies and classifies key entities within text, enabling machines to understand and process human language more effectively. From enhancing search engines and chatbots to powering customer support and financial analysis, NER has diverse applications across various industries. While challenges remain in areas like ambiguity resolution and handling unstructured data, ongoing advancements, particularly in deep learning, promise to further refine NER’s capabilities and expand its impact in the future.