computer science

Named entity

Named entity is a computer science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Named entity rather than just read about it. In short: In information extraction, a named entity is a real-world object, such as a person, location, organization, product, etc., that can be denoted with a proper name. It can be abstract or have a physical existence.

Key takeaways

Named entity belongs to computer science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Named entity to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Named entity from memory before moving on to harder problems.

Reference excerpt

In information extraction, a named entity is a real-world object, such as a person, location, organization, product, etc., that can be denoted with a proper name. It can be abstract or have a physical existence. Examples of named entities include Barack Obama, New York City, Volkswagen Golf, or anything else that can be named. Named entities can simply be viewed as entity instances (e.g., New York City is an instance of a city). From a historical perspective, the term Named Entity was coined during the MUC-6 evaluation campaign and contained ENAMEX (entity name expressions e.g. persons, locations and organizations) and NUMEX (numerical expression). A more formal definition can be derived from the rigid designator by Saul Kripke. In the expression "Named Entity", the word "Named" aims to restrict the possible set of entities to only those for which one or many rigid designators stands for the referent. A designator is rigid when it designates the same thing in every possible world. On the contrary, flaccid designators may designate different things in different possible worlds. As an example, consider the sentence, "Biden is the president of the United States". Both "Biden" and the "United States" are named entities since they refer to specific objects (Joe Biden and United States). However, "president" is not a named entity since it can be used to refer to many different objects in different worlds (in different presidential periods referring to different persons, or even in different countries or organizations referring to different people). Rigid designators usually include proper names as well as certain natural terms like biological species and substances. There is also a general agreement in the Named Entity Recognition community to consider temporal and numerical expressions as named entities, such as amounts of money and other types of units, which may violate the rigid designator perspective. The task of recognizing named entities in text is Named Entity Recognition while the task of determining the identity of the named entities mentioned in text is called Named Entity Disambiguation. Both tasks require dedicated algorithms and resources to be addressed.

See also Named-entity recognition (also referred to as entity identification, entity chunking and entity extraction) Entity linking (also referred to as named entity linking (NEL), named entity disambiguation (NED), named entity recognition and disambiguation (NERD) or named entity normalization) Information extraction Knowledge extraction Text mining (also referred to as text data mining) Truecasing Apache OpenNLP spaCy General Architecture for Text Engineering Natural Language Toolkit

References

Worked examples

Example 1 — a first encounter with Named entity

Start with the simplest possible case. Write down what Named entity claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Named entity before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Named entity ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Named entity

In research: Named entity appears in computer science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Named entity in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Named entity is common in secondary-school and first-year university syllabi. It links to neighbouring topics Computational linguistics, Natural language processing, so understanding it makes those chapters shorter.
In everyday life: Look for Named entity outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Named entity” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Named entity in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Named entity means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Named entity out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Named entity in simple terms?

Why does Named entity matter?

Because it connects several computer science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Named entity?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Named entity.