AI Practice and Technologies Interacting with Humans and the Real World — Revision Sheet

1. 📌 Essentials

• NLP enables machines to interpret, understand, and generate human language naturally.
• Classical NLP pipeline: tokenization, morphology/POS tagging, syntax, semantics, pragmatics.
• Word embeddings (static and contextual) represent words as vectors capturing meaning.
• Transformersized NLP with parallel processing and self-attention.
• Large Language Models (LLMs): BERT, GPT, T5, capable of understanding and generating language.
• Practical tools: spaCy (fast, rule-based), Hugging Face (state-of-the-art neural models).
• Responsible NLP: address bias, fairness, privacy, and energy consumption.
• Challenges include ambiguity, context-dependence, and intent recognition.
• Hierarchical flow: raw text → structured understanding → response or action.
• Future trends: instruction tuning, retrieval augmentation, multilingual models, safety.

2. 🧩 Key Structures & Components

• Tokenization — splits text into units (words, subwords).
• Morphology & POS tagging — identifies grammatical forms and parts of speech.
• Syntax parsing — builds sentence structure (trees, dependencies).
• Semantics mapping — assigns meaning to words/phrases.
• Pragmatics — infers speaker intent based on context.
• Word Embeddings — dense vector representations of words.
• Static embeddings — Word2Vec, GloVe; limited polysemy handling.
• Contextual embeddings — BERT, GPT; dynamic, context-aware.
• Neural sequence models — RNNs, LSTMs, attention mechanisms.
• Transformers — parallel, self-attention-based models.
• Large Language Models — encoder-only, decoder-only, encoder–decoder architectures.
• Tools — spaCy, Hugging Face Transformers.

3. 🔬 Functions, Mechanisms & Relationships

• Pipeline flow: raw text → tokenization → morphology/POS → syntax parsing → semantics → pragmatics.
• Embeddings: convert words into vectors; proximity indicates similarity.
• Static vs. contextual embeddings: static (Word2Vec) are fixed; contextual (BERT) change with context.
• Neural models: process sequences, with RNNs/LSTMs capturing order; attention highlights relevant info.
• Transformers: use self-attention to model global context in parallel.
• LLMs: scale models for diverse tasks—classification, translation, generation.
• Tools: implement NLP tasks efficiently; spaCy for speed, Hugging Face for flexibility.
• Responsible NLP: balance accuracy, interpretability, and ethical considerations.

4. 📊 Comparative Table

5. 🗂️ Hierarchical Diagram (ASCII)

NLP & HCI
 ├─ Interaction paradigms
 │   ├─ Button/menu commands
 │   └─ Natural language understanding
 ├─ Classical pipeline
 │   ├─ Tokenization
 │   ├─ Morphology & POS
 │   ├─ Syntax parsing
 │   ├─ Semantics mapping
 │   └─ Pragmatic inference
 ├─ Word representations
 │   ├─ Bag of Words / TF–IDF
 │   ├─ Static embeddings (Word2Vec, GloVe)
 │   └─ Contextual embeddings (BERT, GPT)
 ├─ Neural models
 │   ├─ RNNs / LSTMs
 │   ├─ Attention mechanisms
 │   └─ Transformers
 ├─ Large language models
 │   ├─ Encoder-only (BERT)
 │   ├─ Decoder-only (GPT)
 │   └─ Encoder–decoder (T5, BART)
 ├─ Practical tools
 │   ├─ spaCy
 │   └─ Hugging Face
 └─ Responsible NLP
     ├─ Accuracy vs interpretability
     ├─ Bias, fairness, privacy
     └─ Sustainability

6. ⚠️ High-Yield Pitfalls & Confusions

• Confusing static and contextual embeddings; static cannot handle polysemy well.
• Overlooking the importance of syntax parsing in semantic understanding.
• Assuming larger models always outperform smaller ones without considering resource constraints.
• Misinterpreting bag of words as capturing syntax or context.
• Ignoring bias and fairness issues in large models.
• Believing tokenization is trivial; it varies greatly across languages.
• Overestimating the interpretability of neural models.
• Confusing encoder-only (BERT) with decoder-only (GPT) architectures.

7. ✅ Final Exam Checklist

• Understand the stages of the classical NLP pipeline.
• Differentiate between static and contextual word embeddings.
• Know key models: RNNs, LSTMs, Transformers, BERT, GPT.
• Be familiar with practical NLP tools: spaCy, Hugging Face.
• Recognize the importance of responsible AI: bias, fairness, privacy.
• Comprehend how attention mechanisms improve relevance.
• Know evaluation metrics: F1, BLEU, ROUGE.
• Be aware of sustainability practices: model compression, caching.
• Understand future trends: instruction tuning, retrieval-augmented generation.
• Grasp the hierarchical flow from raw text to meaningful response.
• Recognize challenges: ambiguity, context-dependence, multilinguality.
• Know the differences between model architectures and their applications.
• Be prepared to discuss ethical considerations in deploying NLP systems.

End of Revision Sheet