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A Friendly Guide to Natural Language Processing and How It Powers the AI Around Us

Have you ever wondered how Siri, Alexa or Google Assistant understand our voices and respond? Or how spam filters catch unwanted emails, search engines show relevant results, and online translators convert between languages?

The magic behind all these technologies is called natural language processing (NLP) – a field focused on giving machines the ability to comprehend human language.

In this beginner‘s guide, we‘ll explore:

  • What NLP is
  • How NLP systems work
  • The history and growth of NLP
  • Real-world applications of this fascinating technology
  • Future directions for NLP

So if you‘re curious to learn how machines can understand our human languages, read on!

What Exactly is Natural Language Processing?

In simple terms, NLP refers to techniques that empower computers to make sense of texts, voices, videos or any natural human communication format.

The end goal is to help machines understand the true intent and meaning behind our words rather than just manipulating language syntax and grammar.

For instance, when you say "Alexa, play some classic rock please", NLP techniques enable Alexa to:

  1. Understand this text input involves requesting music of a certain genre
  2. Identify the key parameters – play, classic rock
  3. Determine an appropriate response fulfilling the user‘s spoken intent

Without NLP, Alexa would fail this seemingly simple conversation!

Over the decades, NLP has evolved from strict rule-based systems to advanced machine learning algorithms that keep improving as data grows. Today, NLP lies at the heart of conversations between humans and intelligent virtual assistants like Alexa!

"Alexa, play some classic rock please"

*User Intent Detection powered by NLP* ↓  

(Play music -> classic rock genre -> polite request)

"Now playing your favorite classic rock tracks!"

Current NLP systems can handle an incredible variety of language complexities – comprehending meanings, translating between languages and even generating original essays or commentary!

But getting to this stage has taken decades of groundbreaking research since the origins of this field…

The History and Growth of NLP: A 50 Year Journey

While NLP has recently entered mainstream use, the seeds were planted as far back as the 1950s when scientists first wondered if computers could understand languages.

The decades that followed saw slow but steady progress through research breakthroughs across academia and industry that solved piece by piece the grand puzzle behind human language comprehension.

Let‘s walk through some highlights!

The Early Days: 1950s to 1960s

In 1950, Alan Turing, the father of artificial intelligence, published a seminal paper titled "Computing Machinery and Intelligence" which proposed an "Imitation Game" for testing if machines can exhibit intelligence.

This paper kickstarted work towards language-translation systems based on rules mapping one language to another. The beginnings of modern NLP!

Soon after in 1954, IBM demonstrated a system that could translate Russian sentences into English after hours of manual grammar coding work.

In 1957, Noam Chomsky‘s book Syntactic Structures outlined his ideas on computational grammar – forming the basis of natural language syntax.

"Colorless green ideas sleep furiously" – The famous grammatically-correct sentence from Chomsky‘s book showcasing how syntax need not carry meanings.

But by the 1960s, scientists realized language translation was far harder than substituting words between languages due to the subtle nuances involved.

The early rule-based approaches failed to account for context, cultural differences and the inherent ambiguities within human languages.

Progress stalled as researchers determined new methods were needed moving forwards!

Statistical Rules and Machine Learning: Late 20th Century

By the 1980s, rather than manually coding endless rules, researchers focused on using statistical probabilities to model real-world languages.

Systems were designed to learn generalized patterns and correlations in word usage across passages. For example, phrases were now analyzed for frequency over large bodies of text documents. This became the basis of modern language modeling using math and machine learning.

In certain narrow domains, researchers applied AI and knowledge bases to attempt tasks like machine translation again. However, inaccuracies were still rampant.

In the 1990s, IBM developed a 5,000-word business reports translator, which marked a commercial start even if quality was low.

In 1995, the first search engine Lycos was launched, signaling the beginning of information retrieval using primitive natural language processing capabilities.

By the early 2000s, web data accelerated developments dramatically. As search engines got access to billions of web pages and documents, they could extract word statistics, semantic connections between terms and teach computers to index content for user queries far more accurately.

In 2010, Google Translate was powered by over a trillion(!) words for comprehensive language translation learning.

The Deep Learning Revolution: 2010s to Today

In the 2010s, deep neural networks transformed NLP by learning complex language representations. Using dense layers of neuron-like connections, deep learning models achieved new state-of-the-art results across various language tasks.

Let‘s see a quick example comparing traditional ML and modern DL techniques:

Text Classification Comparison

Task: Label news articles across categories like politics, tech etc.

Traditional ML Approach
  > Extract keywords, sentences as handcrafted features
  > Train classifiers like SVM on these features

Modern DL Approach
  > Feed source text into Transformer Encoders 
  > Words converted to universal embeddings
  > Train deep neural network classfiers on embedding  
      sequences

Rather than relying on engineering input features, deep learning models automatically learn representations capturing semantics, grammar, context and even tone of texts!

Today, massive pretrained models like Google‘s BERT and OpenAI‘s GPT-3 have pushed state-of-the-art even higher across core language tasks and commercial deployments.

NLP now powers numerous intelligent systems we interact with daily – virtual assistants, search engines, translators, ad recommendation engines and more!

Real-World Applications of NLP: The Possibilities are Endless!

While so far we focused on the history of academic research in NLP, today the applications powering businesses and consumer products are even more mind-blowing!

Let‘s see some examples where NLP shines:

Smart Virtual Assistants

Have you asked Alexa or Siri a question recently? Did your smart speaker understand the human language input perfectly to respond back? Well, you just witnessed NLP in action!

You: "Alexa, how‘s the weather today evening?"

Alexa: "Expect showers this evening with temperatures around 18°C"

*NLP breaks down acoustic signals into language  --> detects weather query intent --> generates forecast response!*

Complex language understanding and dialogue systems enable assistants to have conversations spanning multiple turns fluently.

virtual assistants

Sentiment Analysis

Sentiment analysis is used widely across review sites, brands and social media to determine attitudes and opinions within text data at scale.

NLP models identify emotional expressions and categorize them from very negative to very positive automatically, helping companies understand feedback.

For example, Twitter sentiment measured during product launches can suggest strategies to address pain points!

Search Engines

Have you noticed how search engines like Google autocomplete search phrases before you‘ve even finished typing? Or show relevant results despite the diverse ways queries can be structured?

Under the hood, the search engine digestion of language allows matching website content to user intent accurately by handling millions of searches per minute reliably!

search engine

Text Summarization

Rather than reading through raw texts across news, research papers or long product manuals, NLP can auto-generate summaries picking out important highlights.

This enables quick digest of hefty reports to pull out key insights or generate TLDRs of full articles based on identifying central points.

text summarization

From personalized book or news recommendations to improved chatbots for customer service to stronger adaptation across languages, NLP will drive efficiencies through automation and augmentation of language-intensive tasks.

The Future: Where Next for NLP?

In 2022, we are witnessing large language models like PaLM reach an incredible 540 billion parameters (10x GPT-3) pointing towards the future scale of adaptive systems.

With exponentially growing training datasets through web crawl, social media broadcasts and digital publications, as well as advances in specialized hardware like TPUs, we are likely to achieve Artificial General Intelligence – at least in the linguistic sense!

However, there remain open challenges:

  • NLP models today still fail spectacularly in handling nuanced human language phenomena like humor, sarcasm etc. that involve real-world knowledge beyond statistical patterns

  • Bias and unfair inferences by models due to under-represented or problematic training data requiring ethics-focused strategies

  • Potential for malicious use of synthetic text generation threatening trust and authenticity of online content

The coming years are also likely to see disruption of high-language manual occupations like translation, writing and customer service through progressive automation using NLP.

Responsible guard rails and public policy will be needed to account for technological effects on jobs and inequality.

Nonetheless, natural language processing remains an exciting domain lying at the heart of human-AI collaboration and conversations. As this technology keeps maturing, the possibilities remain endless!

So next time you talk with a digital assistant, search engine or even an autonomous vehicle, remember the power of NLP!

Over 50 years of research progressing from early machine translation ambitions to today‘s AI-infused applications continues to bridge the gap steadily between humans and machines when it comes to mastering languages!