--- language: as language_name: AS language_family: indoaryan_eastern tags: - wikilangs - nlp - tokenizer - embeddings - n-gram - markov - wikipedia - monolingual - family-indoaryan_eastern license: mit library_name: wikilangs pipeline_tag: feature-extraction datasets: - omarkamali/wikipedia-monthly dataset_info: name: wikipedia-monthly description: Monthly snapshots of Wikipedia articles across 300+ languages metrics: - name: best_compression_ratio type: compression value: 4.519 - name: best_isotropy type: isotropy value: 0.8484 - name: vocabulary_size type: vocab value: 69383 generated: 2025-12-27 --- # AS - Wikilangs Models ## Comprehensive Research Report & Full Ablation Study This repository contains NLP models trained and evaluated by Wikilangs, specifically on **AS** Wikipedia data. We analyze tokenizers, n-gram models, Markov chains, vocabulary statistics, and word embeddings. ## 📋 Repository Contents ### Models & Assets - Tokenizers (8k, 16k, 32k, 64k) - N-gram models (2, 3, 4-gram) - Markov chains (context of 1, 2, 3 and 4) - Subword N-gram and Markov chains - Embeddings in various sizes and dimensions - Language Vocabulary - Language Statistics ![Performance Dashboard](visualizations/performance_dashboard.png) ### Analysis and Evaluation - [1. Tokenizer Evaluation](#1-tokenizer-evaluation) - [2. N-gram Model Evaluation](#2-n-gram-model-evaluation) - [3. Markov Chain Evaluation](#3-markov-chain-evaluation) - [4. Vocabulary Analysis](#4-vocabulary-analysis) - [5. Word Embeddings Evaluation](#5-word-embeddings-evaluation) - [6. Summary & Recommendations](#6-summary--recommendations) - [Metrics Glossary](#appendix-metrics-glossary--interpretation-guide) - [Visualizations Index](#visualizations-index) --- ## 1. Tokenizer Evaluation ![Tokenizer Compression](visualizations/tokenizer_compression.png) ### Results | Vocab Size | Compression | Avg Token Len | UNK Rate | Total Tokens | |------------|-------------|---------------|----------|--------------| | **8k** | 3.390x | 3.36 | 0.0640% | 1,495,826 | | **16k** | 3.830x | 3.80 | 0.0723% | 1,324,012 | | **32k** | 4.212x | 4.18 | 0.0795% | 1,203,836 | | **64k** | 4.519x 🏆 | 4.48 | 0.0853% | 1,122,074 | ### Tokenization Examples Below are sample sentences tokenized with each vocabulary size: **Sample 1:** `ইউৰেনাচ নামে তলৰ প্ৰৱন্ধসমূহ বুজাব পাৰে: ইউৰেনাচ: সৌৰজগতৰ সপ্তম গ্ৰহ ইউৰেনাচ (...` | Vocab | Tokens | Count | |-------|--------|-------| | 8k | `▁ইউ ৰে না চ ▁নামে ▁তলৰ ▁প্ৰৱ ন্ধ সমূহ ▁বুজাব ... (+28 more)` | 38 | | 16k | `▁ইউৰে না চ ▁নামে ▁তলৰ ▁প্ৰৱ ন্ধ সমূহ ▁বুজাব ▁পাৰে ... (+23 more)` | 33 | | 32k | `▁ইউৰে নাচ ▁নামে ▁তলৰ ▁প্ৰৱন্ধ সমূহ ▁বুজাব ▁পাৰে : ▁ইউৰে ... (+18 more)` | 28 | | 64k | `▁ইউৰে নাচ ▁নামে ▁তলৰ ▁প্ৰৱন্ধ সমূহ ▁বুজাব ▁পাৰে : ▁ইউৰে ... (+17 more)` | 27 | **Sample 2:** `শ্ৰেণী:ভাৰতীয় অভিনেত্ৰী শ্ৰেণী:জীৱিত ব্যক্তি শ্ৰেণী:ভাৰতীয় ৰাজনীতিবিদ শ্ৰেণী:ভ...` | Vocab | Tokens | Count | |-------|--------|-------| | 8k | `▁শ্ৰেণী : ভাৰতীয় ▁অভিনেত্ৰী ▁শ্ৰেণী : জীৱিত ▁ব্যক্তি ▁শ্ৰেণী : ... (+9 more)` | 19 | | 16k | `▁শ্ৰেণী : ভাৰতীয় ▁অভিনেত্ৰী ▁শ্ৰেণী : জীৱিত ▁ব্যক্তি ▁শ্ৰেণী : ... (+8 more)` | 18 | | 32k | `▁শ্ৰেণী : ভাৰতীয় ▁অভিনেত্ৰী ▁শ্ৰেণী : জীৱিত ▁ব্যক্তি ▁শ্ৰেণী : ... (+8 more)` | 18 | | 64k | `▁শ্ৰেণী : ভাৰতীয় ▁অভিনেত্ৰী ▁শ্ৰেণী : জীৱিত ▁ব্যক্তি ▁শ্ৰেণী : ... (+7 more)` | 17 | **Sample 3:** `তাল বুলিলে তলৰ পৃষ্ঠাসমূহ বুজাব পাৰে: তাল (বাদ্যযন্ত্ৰ) তাল (সংগীত) তাল (ফল)` | Vocab | Tokens | Count | |-------|--------|-------| | 8k | `▁তাল ▁বুল িলে ▁তলৰ ▁পৃষ্ঠ াসমূহ ▁বুজাব ▁পাৰে : ▁তাল ... (+13 more)` | 23 | | 16k | `▁তাল ▁বুলিলে ▁তলৰ ▁পৃষ্ঠ াসমূহ ▁বুজাব ▁পাৰে : ▁তাল ▁( ... (+11 more)` | 21 | | 32k | `▁তাল ▁বুলিলে ▁তলৰ ▁পৃষ্ঠ াসমূহ ▁বুজাব ▁পাৰে : ▁তাল ▁( ... (+11 more)` | 21 | | 64k | `▁তাল ▁বুলিলে ▁তলৰ ▁পৃষ্ঠাসমূহ ▁বুজাব ▁পাৰে : ▁তাল ▁( বাদ্যযন্ত্ৰ ... (+9 more)` | 19 | ### Key Findings - **Best Compression:** 64k achieves 4.519x compression - **Lowest UNK Rate:** 8k with 0.0640% unknown tokens - **Trade-off:** Larger vocabularies improve compression but increase model size - **Recommendation:** 32k vocabulary provides optimal balance for production use --- ## 2. N-gram Model Evaluation ![N-gram Perplexity](visualizations/ngram_perplexity.png) ![N-gram Coverage](visualizations/ngram_coverage.png) ### Results | N-gram | Perplexity | Entropy | Unique N-grams | Top-100 Coverage | Top-1000 Coverage | |--------|------------|---------|----------------|------------------|-------------------| | **2-gram** | 2,255 🏆 | 11.14 | 144,083 | 37.8% | 74.6% | | **2-gram** | 712 🏆 | 9.48 | 14,933 | 47.2% | 91.5% | | **3-gram** | 20,803 | 14.34 | 558,435 | 14.3% | 40.2% | | **3-gram** | 6,279 | 12.62 | 135,792 | 17.8% | 52.9% | | **4-gram** | 109,133 | 16.74 | 1,749,119 | 7.8% | 23.0% | | **4-gram** | 34,064 | 15.06 | 727,754 | 9.4% | 29.5% | ### Top 5 N-grams by Size **2-grams:** | Rank | N-gram | Count | |------|--------|-------| | 1 | `া ৰ` | 608,846 | | 2 | `য ়` | 511,382 | | 3 | `্ ৰ` | 409,497 | | 4 | `প ্` | 302,441 | | 5 | `ি ল` | 296,895 | **3-grams:** | Rank | N-gram | Count | |------|--------|-------| | 1 | `য ় া` | 192,871 | | 2 | `ি য ়` | 190,336 | | 3 | `ী য ়` | 164,267 | | 4 | `ত ে ও` | 138,798 | | 5 | `ে ও ঁ` | 138,171 | **4-grams:** | Rank | N-gram | Count | |------|--------|-------| | 1 | `ত ে ও ঁ` | 137,993 | | 2 | `ি য ় া` | 118,996 | | 3 | `ছ ি ল ।` | 81,488 | | 4 | `ি ছ ি ল` | 71,229 | | 5 | `শ ্ ৰ ে` | 58,374 | ### Key Findings - **Best Perplexity:** 2-gram with 712 - **Entropy Trend:** Decreases with larger n-grams (more predictable) - **Coverage:** Top-1000 patterns cover ~29% of corpus - **Recommendation:** 4-gram or 5-gram for best predictive performance --- ## 3. Markov Chain Evaluation ![Markov Entropy](visualizations/markov_entropy.png) ![Markov Branching](visualizations/markov_branching.png) ### Results | Context | Avg Entropy | Perplexity | Branching Factor | Unique Contexts | Predictability | |---------|-------------|------------|------------------|-----------------|----------------| | **1** | 0.5873 | 1.502 | 6.01 | 178,570 | 41.3% | | **1** | 1.0627 | 2.089 | 7.96 | 5,555 | 0.0% | | **2** | 0.3625 | 1.286 | 2.70 | 1,073,346 | 63.7% | | **2** | 0.9491 | 1.931 | 6.70 | 44,224 | 5.1% | | **3** | 0.2925 | 1.225 | 2.07 | 2,893,182 | 70.7% | | **3** | 0.8311 | 1.779 | 4.51 | 296,427 | 16.9% | | **4** | 0.2472 🏆 | 1.187 | 1.70 | 5,984,484 | 75.3% | | **4** | 0.6476 🏆 | 1.567 | 2.96 | 1,337,967 | 35.2% | ### Generated Text Samples Below are text samples generated from each Markov chain model: **Context Size 1:** 1. `া লয ় যদ ি ল ৰ া ন ে । পৰ ি ছ া উৰ` 2. `্ চত ভ া শ ্ ট ো ক ভ ু ১ট া ’ ল ্` 3. `ি য ় , ক া ল । ইয ় ন কৰ ম ৃ ষকসকলক প` **Context Size 2:** 1. `া ৰ ব ি ব া গ া ঁ ৱত কচ ্ ‌ ২০০৫ – ২০১০ চনত` 2. `য ় া ৰ ব ি প ি ছত anthropological survey of hinduism today , march 2009` 3. `্ ৰ া থম ি ক ব ি ন ্ দ ্ ব া ৰ ব ি` **Context Size 3:** 1. `য ় া ষ ্ ট ে চনত আশ ্ ৰফ ে চৰ১৯৬৮ফ ি ল ্ ল ী` 2. `ি য ় া ধ ী ন হয ় আৰ ু মহ ি ল া ৰ দ ৌ` 3. `ী য ় া ল ো কগ া থ া ক ে ব ি ব া হৰ ব` **Context Size 4:** 1. `ত ে ও ঁ ৰ প ু ৰণ ি ড ি মৰ ু গছৰ পৰ া প ্ ৰ` 2. `ি য ় া চ ি ন ্ ত ু স ে ই বছৰত ে ত ে ও ঁ` 3. `ছ ি ল । ইয ় া ৰ অন ু ম ো দ ী ৰ ্ ঘদ ি ন` ### Key Findings - **Best Predictability:** Context-4 with 75.3% predictability - **Branching Factor:** Decreases with context size (more deterministic) - **Memory Trade-off:** Larger contexts require more storage (1,337,967 contexts) - **Recommendation:** Context-3 or Context-4 for text generation --- ## 4. Vocabulary Analysis ![Zipf's Law](visualizations/zipf_law.png) ![Top Words](visualizations/top20_words.png) ![Coverage Curve](visualizations/vocab_coverage.png) ### Statistics | Metric | Value | |--------|-------| | Vocabulary Size | 69,383 | | Total Tokens | 22,699,994 | | Mean Frequency | 327.17 | | Median Frequency | 4 | | Frequency Std Dev | 13137.34 | ### Most Common Words | Rank | Word | Frequency | |------|------|-----------| | 1 | ৰ | 1,751,445 | | 2 | ত | 1,226,468 | | 3 | ব | 988,164 | | 4 | য | 983,360 | | 5 | ক | 951,103 | | 6 | ন | 878,240 | | 7 | ল | 815,336 | | 8 | প | 750,050 | | 9 | ম | 610,982 | | 10 | স | 521,058 | ### Least Common Words (from vocabulary) | Rank | Word | Frequency | |------|------|-----------| | 1 | zns | 2 | | 2 | tuklas | 2 | | 3 | bilqees | 2 | | 4 | surbhi | 2 | | 5 | ullasamga | 2 | | 6 | utsahamga | 2 | | 7 | manchস | 2 | | 8 | swfl | 2 | | 9 | manhunt | 2 | | 10 | megamodel | 2 | ### Zipf's Law Analysis | Metric | Value | |--------|-------| | Zipf Coefficient | 1.5303 | | R² (Goodness of Fit) | 0.997399 | | Adherence Quality | **excellent** | ### Coverage Analysis | Top N Words | Coverage | |-------------|----------| | Top 100 | 78.6% | | Top 1,000 | 93.9% | | Top 5,000 | 97.8% | | Top 10,000 | 98.6% | ### Key Findings - **Zipf Compliance:** R²=0.9974 indicates excellent adherence to Zipf's law - **High Frequency Dominance:** Top 100 words cover 78.6% of corpus - **Long Tail:** 59,383 words needed for remaining 1.4% coverage --- ## 5. Word Embeddings Evaluation ![Embedding Isotropy](visualizations/embedding_isotropy.png) ![Similarity Matrix](visualizations/embedding_similarity.png) ![t-SNE Words](visualizations/tsne_words.png) ![t-SNE Sentences](visualizations/tsne_sentences.png) ### Model Comparison | Model | Vocab Size | Dimension | Avg Norm | Std Norm | Isotropy | |-------|------------|-----------|----------|----------|----------| | **mono_32d** | 113,429 | 32 | 3.011 | 0.609 | 0.8484 🏆 | | **mono_64d** | 113,429 | 64 | 3.498 | 0.644 | 0.8482 | | **mono_128d** | 113,429 | 128 | 4.089 | 0.704 | 0.8254 | | **embeddings_enhanced** | 0 | 0 | 0.000 | 0.000 | 0.0000 | ### Key Findings - **Best Isotropy:** mono_32d with 0.8484 (more uniform distribution) - **Dimension Trade-off:** Higher dimensions capture more semantics but reduce isotropy - **Vocabulary Coverage:** All models cover 113,429 words - **Recommendation:** 100d for balanced semantic capture and efficiency --- ## 6. Summary & Recommendations ![Performance Dashboard](visualizations/performance_dashboard.png) ### Production Recommendations | Component | Recommended | Rationale | |-----------|-------------|-----------| | Tokenizer | **32k BPE** | Best compression (4.52x) with low UNK rate | | N-gram | **5-gram** | Lowest perplexity (712) | | Markov | **Context-4** | Highest predictability (75.3%) | | Embeddings | **100d** | Balanced semantic capture and isotropy | --- ## Appendix: Metrics Glossary & Interpretation Guide This section provides definitions, intuitions, and guidance for interpreting the metrics used throughout this report. ### Tokenizer Metrics **Compression Ratio** > *Definition:* The ratio of characters to tokens (chars/token). Measures how efficiently the tokenizer represents text. > > *Intuition:* Higher compression means fewer tokens needed to represent the same text, reducing sequence lengths for downstream models. A 3x compression means ~3 characters per token on average. > > *What to seek:* Higher is generally better for efficiency, but extremely high compression may indicate overly aggressive merging that loses morphological information. **Average Token Length (Fertility)** > *Definition:* Mean number of characters per token produced by the tokenizer. > > *Intuition:* Reflects the granularity of tokenization. Longer tokens capture more context but may struggle with rare words; shorter tokens are more flexible but increase sequence length. > > *What to seek:* Balance between 2-5 characters for most languages. Arabic/morphologically-rich languages may benefit from slightly longer tokens. **Unknown Token Rate (OOV Rate)** > *Definition:* Percentage of tokens that map to the unknown/UNK token, indicating words the tokenizer cannot represent. > > *Intuition:* Lower OOV means better vocabulary coverage. High OOV indicates the tokenizer encounters many unseen character sequences. > > *What to seek:* Below 1% is excellent; below 5% is acceptable. BPE tokenizers typically achieve very low OOV due to subword fallback. ### N-gram Model Metrics **Perplexity** > *Definition:* Measures how "surprised" the model is by test data. Mathematically: 2^(cross-entropy). Lower values indicate better prediction. > > *Intuition:* If perplexity is 100, the model is as uncertain as if choosing uniformly among 100 options at each step. A perplexity of 10 means effectively choosing among 10 equally likely options. > > *What to seek:* Lower is better. Perplexity decreases with larger n-grams (more context). Values vary widely by language and corpus size. **Entropy** > *Definition:* Average information content (in bits) needed to encode the next token given the context. Related to perplexity: perplexity = 2^entropy. > > *Intuition:* High entropy means high uncertainty/randomness; low entropy means predictable patterns. Natural language typically has entropy between 1-4 bits per character. > > *What to seek:* Lower entropy indicates more predictable text patterns. Entropy should decrease as n-gram size increases. **Coverage (Top-K)** > *Definition:* Percentage of corpus occurrences explained by the top K most frequent n-grams. > > *Intuition:* High coverage with few patterns indicates repetitive/formulaic text; low coverage suggests diverse vocabulary usage. > > *What to seek:* Depends on use case. For language modeling, moderate coverage (40-60% with top-1000) is typical for natural text. ### Markov Chain Metrics **Average Entropy** > *Definition:* Mean entropy across all contexts, measuring average uncertainty in next-word prediction. > > *Intuition:* Lower entropy means the model is more confident about what comes next. Context-1 has high entropy (many possible next words); Context-4 has low entropy (few likely continuations). > > *What to seek:* Decreasing entropy with larger context sizes. Very low entropy (<0.1) indicates highly deterministic transitions. **Branching Factor** > *Definition:* Average number of unique next tokens observed for each context. > > *Intuition:* High branching = many possible continuations (flexible but uncertain); low branching = few options (predictable but potentially repetitive). > > *What to seek:* Branching factor should decrease with context size. Values near 1.0 indicate nearly deterministic chains. **Predictability** > *Definition:* Derived metric: (1 - normalized_entropy) × 100%. Indicates how deterministic the model's predictions are. > > *Intuition:* 100% predictability means the next word is always certain; 0% means completely random. Real text falls between these extremes. > > *What to seek:* Higher predictability for text generation quality, but too high (>98%) may produce repetitive output. ### Vocabulary & Zipf's Law Metrics **Zipf's Coefficient** > *Definition:* The slope of the log-log plot of word frequency vs. rank. Zipf's law predicts this should be approximately -1. > > *Intuition:* A coefficient near -1 indicates the corpus follows natural language patterns where a few words are very common and most words are rare. > > *What to seek:* Values between -0.8 and -1.2 indicate healthy natural language distribution. Deviations may suggest domain-specific or artificial text. **R² (Coefficient of Determination)** > *Definition:* Measures how well the linear fit explains the frequency-rank relationship. Ranges from 0 to 1. > > *Intuition:* R² near 1.0 means the data closely follows Zipf's law; lower values indicate deviation from expected word frequency patterns. > > *What to seek:* R² > 0.95 is excellent; > 0.99 indicates near-perfect Zipf adherence typical of large natural corpora. **Vocabulary Coverage** > *Definition:* Cumulative percentage of corpus tokens accounted for by the top N words. > > *Intuition:* Shows how concentrated word usage is. If top-100 words cover 50% of text, the corpus relies heavily on common words. > > *What to seek:* Top-100 covering 30-50% is typical. Higher coverage indicates more repetitive text; lower suggests richer vocabulary. ### Word Embedding Metrics **Isotropy** > *Definition:* Measures how uniformly distributed vectors are in the embedding space. Computed as the ratio of minimum to maximum singular values. > > *Intuition:* High isotropy (near 1.0) means vectors spread evenly in all directions; low isotropy means vectors cluster in certain directions, reducing expressiveness. > > *What to seek:* Higher isotropy generally indicates better-quality embeddings. Values > 0.1 are reasonable; > 0.3 is good. Lower-dimensional embeddings tend to have higher isotropy. **Average Norm** > *Definition:* Mean magnitude (L2 norm) of word vectors in the embedding space. > > *Intuition:* Indicates the typical "length" of vectors. Consistent norms suggest stable training; high variance may indicate some words are undertrained. > > *What to seek:* Relatively consistent norms across models. The absolute value matters less than consistency (low std deviation). **Cosine Similarity** > *Definition:* Measures angular similarity between vectors, ranging from -1 (opposite) to 1 (identical direction). > > *Intuition:* Words with similar meanings should have high cosine similarity. This is the standard metric for semantic relatedness in embeddings. > > *What to seek:* Semantically related words should score > 0.5; unrelated words should be near 0. Synonyms often score > 0.7. **t-SNE Visualization** > *Definition:* t-Distributed Stochastic Neighbor Embedding - a dimensionality reduction technique that preserves local structure for visualization. > > *Intuition:* Clusters in t-SNE plots indicate groups of semantically related words. Spread indicates vocabulary diversity; tight clusters suggest semantic coherence. > > *What to seek:* Meaningful clusters (e.g., numbers together, verbs together). Avoid over-interpreting distances - t-SNE preserves local, not global, structure. ### General Interpretation Guidelines 1. **Compare within model families:** Metrics are most meaningful when comparing models of the same type (e.g., 8k vs 64k tokenizer). 2. **Consider trade-offs:** Better performance on one metric often comes at the cost of another (e.g., compression vs. OOV rate). 3. **Context matters:** Optimal values depend on downstream tasks. Text generation may prioritize different metrics than classification. 4. **Corpus influence:** All metrics are influenced by corpus characteristics. Wikipedia text differs from social media or literature. 5. **Language-specific patterns:** Morphologically rich languages (like Arabic) may show different optimal ranges than analytic languages. ### Visualizations Index | Visualization | Description | |---------------|-------------| | Tokenizer Compression | Compression ratios by vocabulary size | | Tokenizer Fertility | Average token length by vocabulary | | Tokenizer OOV | Unknown token rates | | Tokenizer Total Tokens | Total tokens by vocabulary | | N-gram Perplexity | Perplexity by n-gram size | | N-gram Entropy | Entropy by n-gram size | | N-gram Coverage | Top pattern coverage | | N-gram Unique | Unique n-gram counts | | Markov Entropy | Entropy by context size | | Markov Branching | Branching factor by context | | Markov Contexts | Unique context counts | | Zipf's Law | Frequency-rank distribution with fit | | Vocab Frequency | Word frequency distribution | | Top 20 Words | Most frequent words | | Vocab Coverage | Cumulative coverage curve | | Embedding Isotropy | Vector space uniformity | | Embedding Norms | Vector magnitude distribution | | Embedding Similarity | Word similarity heatmap | | Nearest Neighbors | Similar words for key terms | | t-SNE Words | 2D word embedding visualization | | t-SNE Sentences | 2D sentence embedding visualization | | Position Encoding | Encoding method comparison | | Model Sizes | Storage requirements | | Performance Dashboard | Comprehensive performance overview | --- ## About This Project ### Data Source Models trained on [wikipedia-monthly](https://huggingface.co/datasets/omarkamali/wikipedia-monthly) - a monthly snapshot of Wikipedia articles across 300+ languages. ### Project A project by **[Wikilangs](https://wikilangs.org)** - Open-source NLP models for every Wikipedia language. ### Maintainer [Omar Kamali](https://omarkamali.com) - [Omneity Labs](https://omneitylabs.com) ### Citation If you use these models in your research, please cite: ```bibtex @misc{wikilangs2025, author = {Kamali, Omar}, title = {Wikilangs: Open NLP Models for Wikipedia Languages}, year = {2025}, publisher = {HuggingFace}, url = {https://huggingface.co/wikilangs} institution = {Omneity Labs} } ``` ### License MIT License - Free for academic and commercial use. ### Links - 🌐 Website: [wikilangs.org](https://wikilangs.org) - 🤗 Models: [huggingface.co/wikilangs](https://huggingface.co/wikilangs) - 📊 Data: [wikipedia-monthly](https://huggingface.co/datasets/omarkamali/wikipedia-monthly) - 👤 Author: [Omar Kamali](https://huggingface.co/omarkamali) --- *Generated by Wikilangs Models Pipeline* *Report Date: 2025-12-27 18:45:07*