Popular Embedding Techniques in AI
Embedding techniques are essential in AI, particularly in Natural Language Processing (NLP), where they help convert text data into numerical representations that models can understand.
Here’s an overview of the most popular embedding techniques and how they work:
1. Word2Vec (2013 by Google)
Word2Vec is one of the first breakthroughs in word embeddings.
✅ How It Works:
- It learns word embeddings by predicting the context of a word.
- Uses two models:
- CBOW (Continuous Bag of Words): Predicts the current word from surrounding words.
- Skip-Gram: Predicts surrounding words from the current word.
✅ Example: If the sentence is: 👉 "I love playing football"
- CBOW will learn to predict "love" from "I" and "playing".
- Skip-Gram will learn to predict "I" and "playing" from "love".
📌 Pros:
-
Fast and efficient.
-
Captures semantic relationships like:
King - Man + Woman = Queen
❌ Cons:
- Doesn't consider word order.
- Struggles with polysemy (words with multiple meanings like "bank").
2. GloVe (Global Vectors for Word Representation, 2014 by Stanford)
GloVe combines the best of both count-based and prediction-based models.
✅ How It Works:
- It builds a word co-occurrence matrix.
- Factorizes this matrix to create word embeddings.
- Words that appear in similar contexts have similar vectors.
✅ Example:
- "Ice" and "Snow" will have similar vectors.
- "Ice" and "Steam" will have dissimilar vectors.
📌 Pros:
- Captures both local and global word meaning.
- Pre-trained models available.
❌ Cons:
- Fixed vocabulary size.
- Doesn't handle polysemy.
3. BERT Embeddings (2018 by Google)
BERT (Bidirectional Encoder Representations from Transformers) revolutionized NLP by using contextual embeddings.
✅ How It Works:
- It uses a Transformer architecture to learn word meaning based on surrounding context (both left and right).
- Words have different embeddings depending on the sentence.
✅ Example:
- "The bank is near the river."
- "I need to go to the bank to deposit money."
BERT will assign different vectors to the word "bank" in each sentence.
📌 Pros:
- Handles polysemy.
- Context-aware embeddings.
- Pre-trained on massive datasets like Wikipedia.
❌ Cons:
- Computationally expensive.
- Requires a lot of data.
4. Sentence Transformers (SBERT, 2019 by Google and UKP Lab)
Sentence Transformers generate embeddings for entire sentences or paragraphs, not just individual words.
✅ How It Works:
- Fine-tunes BERT or other Transformer models to generate fixed-length sentence embeddings.
- Can be used for tasks like semantic search, clustering, and paraphrase detection.
✅ Example:
- "I love AI" →
[0.3, 0.8, 0.2, ...] - "AI is amazing" → Similar embedding
📌 Pros:
- Captures sentence meaning.
- Efficient and faster than BERT for sentence-level tasks.
❌ Cons:
- Requires fine-tuning for best performance.
5. ELMo (Embeddings from Language Models, 2018 by AllenNLP)
ELMo generates contextual embeddings by considering the entire sentence.
✅ How It Works:
- Uses bi-directional LSTM layers.
- Words have different representations depending on their sentence context.
✅ Example:
- "The apple is red."
- "Apple is a tech company."
ELMo will assign different embeddings to "Apple" in each sentence.
📌 Pros:
- Contextual embeddings.
- Handles polysemy.
❌ Cons:
- Heavier model compared to Word2Vec or GloVe.
Which One Should You Use?
| Technique | Contextual | Word-Level | Sentence-Level | Speed | Best For |
|---|---|---|---|---|---|
| Word2Vec | ❌ | ✅ | ❌ | 🔥 Fast | Basic word representations |
| GloVe | ❌ | ✅ | ❌ | 🔥 Fast | Pre-trained word embeddings |
| BERT | ✅ | ✅ | ✅ | 🐢 Slow | Context-aware NLP tasks |
| Sentence Transformers | ✅ | ❌ | ✅ | 🚀 Fast | Semantic search, clustering |
| ELMo | ✅ | ✅ | ❌ | 🐢 Slow | Polysemy-rich datasets |
Final Thoughts
- If you're working on simple NLP tasks → Use Word2Vec or GloVe.
- For context-sensitive tasks → Use BERT or Sentence Transformers.
- If you're building chatbots or semantic search engines → Use Sentence Transformers.
Comments
Post a Comment