README.md

---
language: chr
language_name: Cherokee
language_family: american_iroquoian
tags:
  - wikilangs
  - nlp
  - tokenizer
  - embeddings
  - n-gram
  - markov
  - wikipedia
  - feature-extraction
  - sentence-similarity
  - tokenization
  - n-grams
  - markov-chain
  - text-mining
  - fasttext
  - babelvec
  - vocabulous
  - vocabulary
  - monolingual
  - family-american_iroquoian
license: mit
library_name: wikilangs
pipeline_tag: text-generation
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: 3.552
  - name: best_isotropy
    type: isotropy
    value: 0.2412
  - name: vocabulary_size
    type: vocab
    value: 0
generated: 2026-01-03
---

# Cherokee - Wikilangs Models
## Comprehensive Research Report & Full Ablation Study

This repository contains NLP models trained and evaluated by Wikilangs, specifically on **Cherokee** 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, 5-gram)
- Markov chains (context of 1, 2, 3, 4 and 5)
- Subword N-gram and Markov chains
- Embeddings in various sizes and dimensions (aligned and unaligned)
- 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. Morphological Analysis (Experimental)](#6--morphological-analysis-experimental)
- [7. Summary & Recommendations](#7-summary--recommendations)
- [Metrics Glossary](#appendix-metrics-glossary--interpretation-guide)
- [Visualizations Index](#visualizations-index)

---
## 1. Tokenizer Evaluation

![Tokenizer Compression](visualizations/tokenizer_compression.png)

![Tokenizer Fertility](visualizations/tokenizer_fertility.png)

![Tokenizer OOV](visualizations/tokenizer_oov.png)

![Total Tokens](visualizations/tokenizer_total_tokens.png)

### Results

| Vocab Size | Compression | Avg Token Len | UNK Rate | Total Tokens |
|------------|-------------|---------------|----------|--------------|
| **8k** | 2.919x | 2.93 | 0.1472% | 82,177 |
| **16k** | 3.358x | 3.37 | 0.1694% | 71,429 |
| **32k** | 3.552x 🏆 | 3.57 | 0.1792% | 67,524 |

### Tokenization Examples

Below are sample sentences tokenized with each vocabulary size:

**Sample 1:** `ᏅᏓᎩ"Consortium Word List." (nvdagi) () ᎦᏚᎲᎢ ᎡᏉ ᏄᏲᎪᎢ, ᏄᏲᎩ, ᎠᎹᏰᏟ. ᏙᏯᏗᏢ ᏗᏕᎬᏔᏛ be ch...`

| Vocab | Tokens | Count |
|-------|--------|-------|
| 8k | `▁ᏅᏓᎩ " consortium ▁word ▁list ." ▁( nvda gi ) ... (+13 more)` | 23 |
| 16k | `▁ᏅᏓᎩ " consortium ▁word ▁list ." ▁( nvdagi ) ▁() ... (+12 more)` | 22 |
| 32k | `▁ᏅᏓᎩ " consortium ▁word ▁list ." ▁( nvdagi ) ▁() ... (+12 more)` | 22 |

**Sample 2:** `ᏳᏈᎳ"Consortium Word List." (yuquila) (). ᏓᏓᏚᎬ ᎪᏪᎵ ᏙᏯᏗᏢ ᏗᏕᎬᏔᏛ be checked`

| Vocab | Tokens | Count |
|-------|--------|-------|
| 8k | `▁Ᏻ Ꮘ Ꮃ " consortium ▁word ▁list ." ▁( yu ... (+9 more)` | 19 |
| 16k | `▁ᏳᏈᎳ " consortium ▁word ▁list ." ▁( yuquila ) ▁(). ... (+6 more)` | 16 |
| 32k | `▁ᏳᏈᎳ " consortium ▁word ▁list ." ▁( yuquila ) ▁(). ... (+6 more)` | 16 |

**Sample 3:** `ᎦᏢᏍᏙᏗ"Consortium Word List." (gatlvsdodi). ᏓᏓᏚᎬ ᎪᏪᎵ ᏙᏯᏗᏢ ᏗᏕᎬᏔᏛ ᎠᎦᏎᏍᏔᏅ be checked`

| Vocab | Tokens | Count |
|-------|--------|-------|
| 8k | `▁Ꭶ Ꮲ ᏍᏙᏗ " consortium ▁word ▁list ." ▁( gat ... (+10 more)` | 20 |
| 16k | `▁ᎦᏢᏍᏙᏗ " consortium ▁word ▁list ." ▁( gatlvs dodi ). ... (+7 more)` | 17 |
| 32k | `▁ᎦᏢᏍᏙᏗ " consortium ▁word ▁list ." ▁( gatlvsdodi ). ▁ᏓᏓᏚᎬ ... (+6 more)` | 16 |


### Key Findings

- **Best Compression:** 32k achieves 3.552x compression
- **Lowest UNK Rate:** 8k with 0.1472% 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 Unique](visualizations/ngram_unique.png)

![N-gram Coverage](visualizations/ngram_coverage.png)

### Results

| N-gram | Variant | Perplexity | Entropy | Unique N-grams | Top-100 Coverage | Top-1000 Coverage |
|--------|---------|------------|---------|----------------|------------------|-------------------|
| **2-gram** | Word | 151 🏆 | 7.24 | 471 | 68.7% | 100.0% |
| **2-gram** | Subword | 931 | 9.86 | 3,244 | 40.2% | 86.2% |
| **3-gram** | Word | 218 | 7.76 | 655 | 63.6% | 100.0% |
| **3-gram** | Subword | 4,428 | 12.11 | 12,716 | 22.1% | 52.3% |
| **4-gram** | Word | 483 | 8.91 | 1,256 | 49.2% | 90.8% |
| **4-gram** | Subword | 9,728 | 13.25 | 28,356 | 18.7% | 39.4% |
| **5-gram** | Word | 414 | 8.69 | 901 | 51.7% | 100.0% |
| **5-gram** | Subword | 9,506 | 13.21 | 27,480 | 20.2% | 39.5% |

### Top 5 N-grams by Size

**2-grams (Word):**

| Rank | N-gram | Count |
|------|--------|-------|
| 1 | `be checked` | 841 |
| 2 | `ꮩꮿꮧꮲ ꮧꮥꭼꮤꮫ` | 577 |
| 3 | `ꮣꮣꮪꭼ ꭺꮺꮅ` | 470 |
| 4 | `ꭺꮺꮅ ꮩꮿꮧꮲ` | 430 |
| 5 | `word list` | 344 |

**3-grams (Word):**

| Rank | N-gram | Count |
|------|--------|-------|
| 1 | `ꮣꮣꮪꭼ ꭺꮺꮅ ꮩꮿꮧꮲ` | 430 |
| 2 | `ꭺꮺꮅ ꮩꮿꮧꮲ ꮧꮥꭼꮤꮫ` | 430 |
| 3 | `consortium word list` | 342 |
| 4 | `ꮧꮥꭼꮤꮫ be checked` | 226 |
| 5 | `ꮩꮿꮧꮲ ꮧꮥꭼꮤꮫ be` | 215 |

**4-grams (Word):**

| Rank | N-gram | Count |
|------|--------|-------|
| 1 | `ꮣꮣꮪꭼ ꭺꮺꮅ ꮩꮿꮧꮲ ꮧꮥꭼꮤꮫ` | 430 |
| 2 | `ꮩꮿꮧꮲ ꮧꮥꭼꮤꮫ be checked` | 215 |
| 3 | `ꭺꮺꮅ ꮩꮿꮧꮲ ꮧꮥꭼꮤꮫ be` | 162 |
| 4 | `ꭺꮺꮅ ꮩꮿꮧꮲ ꮧꮥꭼꮤꮫ ꭰꭶꮞꮝꮤꮕ` | 96 |
| 5 | `ꮩꮿꮧꮲ ꮧꮥꭼꮤꮫ ꭰꭶꮞꮝꮤꮕ be` | 96 |

**5-grams (Word):**

| Rank | N-gram | Count |
|------|--------|-------|
| 1 | `ꭺꮺꮅ ꮩꮿꮧꮲ ꮧꮥꭼꮤꮫ be checked` | 162 |
| 2 | `ꮣꮣꮪꭼ ꭺꮺꮅ ꮩꮿꮧꮲ ꮧꮥꭼꮤꮫ be` | 162 |
| 3 | `ꮩꮿꮧꮲ ꮧꮥꭼꮤꮫ ꭰꭶꮞꮝꮤꮕ be checked` | 96 |
| 4 | `ꭺꮺꮅ ꮩꮿꮧꮲ ꮧꮥꭼꮤꮫ ꭰꭶꮞꮝꮤꮕ be` | 96 |
| 5 | `ꮣꮣꮪꭼ ꭺꮺꮅ ꮩꮿꮧꮲ ꮧꮥꭼꮤꮫ ꭰꭶꮞꮝꮤꮕ` | 96 |

**2-grams (Subword):**

| Rank | N-gram | Count |
|------|--------|-------|
| 1 | `_ ꭰ` | 5,288 |
| 2 | `_ ꭴ` | 3,380 |
| 3 | `ꮧ _` | 2,778 |
| 4 | `. _` | 2,562 |
| 5 | `, _` | 2,084 |

**3-grams (Subword):**

| Rank | N-gram | Count |
|------|--------|-------|
| 1 | `ꮝ ꮧ _` | 1,355 |
| 2 | `_ c h` | 978 |
| 3 | `c h e` | 956 |
| 4 | `_ ꭰ ꮄ` | 955 |
| 5 | `ꮧ ꮲ _` | 882 |

**4-grams (Subword):**

| Rank | N-gram | Count |
|------|--------|-------|
| 1 | `_ c h e` | 909 |
| 2 | `_ ꭰ ꮄ _` | 874 |
| 3 | `e _ c h` | 848 |
| 4 | `_ b e _` | 842 |
| 5 | `c h e c` | 841 |

**5-grams (Subword):**

| Rank | N-gram | Count |
|------|--------|-------|
| 1 | `e _ c h e` | 846 |
| 2 | `_ c h e c` | 841 |
| 3 | `e c k e d` | 841 |
| 4 | `_ b e _ c` | 841 |
| 5 | `c h e c k` | 841 |


### Key Findings

- **Best Perplexity:** 2-gram (word) with 151
- **Entropy Trend:** Decreases with larger n-grams (more predictable)
- **Coverage:** Top-1000 patterns cover ~40% of corpus
- **Recommendation:** 4-gram or 5-gram for best predictive performance

---
## 3. Markov Chain Evaluation

![Markov Entropy](visualizations/markov_entropy.png)

![Markov Contexts](visualizations/markov_contexts.png)

![Markov Branching](visualizations/markov_branching.png)

### Results

| Context | Variant | Avg Entropy | Perplexity | Branching Factor | Unique Contexts | Predictability |
|---------|---------|-------------|------------|------------------|-----------------|----------------|
| **1** | Word | 0.4882 | 1.403 | 2.29 | 13,116 | 51.2% |
| **1** | Subword | 1.6098 | 3.052 | 16.02 | 447 | 0.0% |
| **2** | Word | 0.0920 | 1.066 | 1.15 | 29,975 | 90.8% |
| **2** | Subword | 1.0061 | 2.008 | 4.67 | 7,162 | 0.0% |
| **3** | Word | 0.0290 | 1.020 | 1.05 | 34,378 | 97.1% |
| **3** | Subword | 0.5823 | 1.497 | 2.32 | 33,475 | 41.8% |
| **4** | Word | 0.0141 🏆 | 1.010 | 1.02 | 35,846 | 98.6% |
| **4** | Subword | 0.2760 | 1.211 | 1.46 | 77,796 | 72.4% |

### Generated Text Samples (Word-based)

Below are text samples generated from each word-based Markov chain model:

**Context Size 1:**

1. `ꭰꮄ ꭳꮒꮿꭸꮝꮩꮧ ꭳꭶꮃꮀꮋ contributed ꮎꭵ ꮝꮖꮄꮝꮧ ᏹꮹꭹ ꮮꭶ ꮵꮿꮢꮒꮅꮩꮈꭲ ꮓꮚꮕ ꭳꭹꮎꮅꮝꮣᏼꮕꭲ ꭰꮳꮧ ꮄꭼꮎꮋ animalia ꭰꮭꭵꭲ phylum`
2. `be checked ꮪꮎꮩꮲꮹꮧꮢ be checked ꭱꮃꮧꮬ ꭰꮥꮫꮝꭺꭲ ꭶꮳꮔꮃ ꭴꮭꮕꮣꮥꮂ ꭰꮣꮕꮝꮧ ordo artiodactyla ꮟꮣꮑꮈꭿ ꭴꮝꮧ subspecies c`
3. `ꭿꭰ 50 41 fꭶꮈꮃꮧ 65 f ꭶꮈꭰꮥꭴ 49 fꭶꮈꮃꮧ 50 ꭷꮓꭾꭽ ꭰᏸꮅ ꭴꮢꭷꮅ ꭿꭰ ꭲᏼ ꭰꮒꮩꮎꭵ`

**Context Size 2:**

1. `ꮩꮿꮧꮲ ꮧꮥꭼꮤꮫ be checked ꮷᏼꮲ ꭰꮉᏸꮯ ꭰꮒꭲꮴꭲᏻꮝꮧ ꭲꮴꭲᏻꮝꮧ ꭰꮒꮼꮒꭽ ꮧꮣꮯꮆꮝꮤꮕ be checked ꭱꮃꮧꮬ ꮖꮗꭲꮴꭹꭲꮒ`
2. `ꮣꮣꮪꭼ ꭺꮺꮅ ꮩꮿꮧꮲ ꮧꮥꭼꮤꮫ be checked ꮷᏼꮲ ꭰꮉᏸꮯ ᏻꮃꮫ ꮣꮆꮒꭶꮝꮫ ꭼꮏꭸꮝꮫ`
3. `ꭺꮺꮅ ꮩꮿꮧꮲ ꮧꮥꭼꮤꮫ ꮳꮃꭹ ꮷꮒᏼꮻ ꭰꮒꮳꭻꭲ ꭸꭺꮞꮈꭲ ꭰꮄ ꮜꮚ ꭴꮝꮧ ꮴꮆꭿ ꮠꮑꮅꮑ safire william the way we`

**Context Size 3:**

1. `ꮣꮣꮪꭼ ꭺꮺꮅ ꮩꮿꮧꮲ ꮧꮥꭼꮤꮫ ꭰꮉᏸꮅ ꮪꮎꮩꮲꮹꮧꮢ be checked`
2. `ꭺꮺꮅ ꮩꮿꮧꮲ ꮧꮥꭼꮤꮫ be checked ꭱꮃꮧꮬ ꮖꮗꭲꮴꭹꭲꮒ`
3. `consortium word list amayutlidi saluyi ꮣꮣꮪꭼ ꭺꮺꮅ ꮩꮿꮧꮲ ꮧꮥꭼꮤꮫ be checked ꭱꮃꮧꮬ ꮖꮗꭲꮴꭹꭲꮒ`

**Context Size 4:**

1. `ꮣꮣꮪꭼ ꭺꮺꮅ ꮩꮿꮧꮲ ꮧꮥꭼꮤꮫ be checked ꮷᏼꮲ ꭰꮉᏸꮯ ᏻꮃꮫ ꮣꮆꮒꭶꮝꮫ ꭼꮏꭸꮝꮫ`
2. `ꭺꮺꮅ ꮩꮿꮧꮲ ꮧꮥꭼꮤꮫ be checked ꭱꮃꮧꮬ`
3. `ꮩꮿꮧꮲ ꮧꮥꭼꮤꮫ ꭰꭶꮞꮝꮤꮕ be checked`


### Generated Text Samples (Subword-based)

Below are text samples generated from each subword-based Markov chain model:

**Context Size 1:**

1. `_ꭿ_-_ꮻꮫ_ꭻꭰꮑꭶꮜꮕꭲ_`
2. `ꮧꮭꭵ_manotatrdo,_`
3. `ꮝꮦꮡꮣꮕꮫꮃꮜꮒꮿꮧ._ꮣꮯ.`

**Context Size 2:**

1. `_ꭰꮑ,_be_ꮳꮃꭹ,_ꭳꮻ_ꮎ`
2. `_ꭴꭼꮻᏻꭿ_ꭶꮑꭶ_ꮒꮧꮝ_ꭲꮿ`
3. `ꮧ_ꮣꮒꭺꮫꮢ_be_ꮣꮣꮄꭹ_ꮧ`

**Context Size 3:**

1. `ꮝꮧ_ꭸꮢꭹ_ꭽꮻꮎꮧꮲ_tassi`
2. `_chemispherokee_na`
3. `checked_(ꭱꮅꮯꮿ_ꭰꮅꮠ_`

**Context Size 4:**

1. `_checked_(ꭱꮃꮧꮬ)_(ꮖꮗ`
2. `_ꭰꮄ_80,000_ꮎꮝꭶꮕꮎ_ꭶꮆ`
3. `e_checked_ꮪᏻꭺꮫ_ꮹꮞꮝꮧ`


### Key Findings

- **Best Predictability:** Context-4 (word) with 98.6% predictability
- **Branching Factor:** Decreases with context size (more deterministic)
- **Memory Trade-off:** Larger contexts require more storage (77,796 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 | 4,160 |
| Total Tokens | 34,218 |
| Mean Frequency | 8.23 |
| Median Frequency | 3 |
| Frequency Std Dev | 35.30 |

### Most Common Words

| Rank | Word | Frequency |
|------|------|-----------|
| 1 | ꭰꮄ | 885 |
| 2 | be | 843 |
| 3 | checked | 841 |
| 4 | ꭿꭰ | 767 |
| 5 | ꮧꮥꭼꮤꮫ | 610 |
| 6 | ꮩꮿꮧꮲ | 579 |
| 7 | ꭺꮺꮅ | 521 |
| 8 | ꮣꮣꮪꭼ | 480 |
| 9 | ꮳꮃꭹ | 468 |
| 10 | word | 345 |

### Least Common Words (from vocabulary)

| Rank | Word | Frequency |
|------|------|-----------|
| 1 | ꭴꮎꮣꮓꭾꮈ | 2 |
| 2 | ꭴꮣꮳꮨꭹ | 2 |
| 3 | ꮧꭸꭶꮣꮣꮑꮧ | 2 |
| 4 | ꭴꮎꮣꭻᏼꭱꮧ | 2 |
| 5 | ꭴꮣꮇꮃ | 2 |
| 6 | ꮧꮓꭾꮅꮣꮝꮧ | 2 |
| 7 | ꭴꮣꮑꮯᏼꮞ | 2 |
| 8 | ꮧꮣꮣꮪꮣꮄꮏꭲ | 2 |
| 9 | ꭶᏸꭺꭹ | 2 |
| 10 | ꮧꭶꮣꮧꮻꮝꮩꮧ | 2 |

### Zipf's Law Analysis

| Metric | Value |
|--------|-------|
| Zipf Coefficient | 0.8676 |
| R² (Goodness of Fit) | 0.984121 |
| Adherence Quality | **excellent** |

### Coverage Analysis

| Top N Words | Coverage |
|-------------|----------|
| Top 100 | 40.0% |
| Top 1,000 | 74.3% |
| Top 5,000 | 0.0% |
| Top 10,000 | 0.0% |

### Key Findings

- **Zipf Compliance:** R²=0.9841 indicates excellent adherence to Zipf's law
- **High Frequency Dominance:** Top 100 words cover 40.0% of corpus
- **Long Tail:** -5,840 words needed for remaining 100.0% 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)


### 5.1 Cross-Lingual Alignment

![Alignment Quality](visualizations/embedding_alignment_quality.png)

![Multilingual t-SNE](visualizations/embedding_tsne_multilingual.png)


### 5.2 Model Comparison

| Model | Dimension | Isotropy | Semantic Density | Alignment R@1 | Alignment R@10 |
|-------|-----------|----------|------------------|---------------|----------------|
| **mono_32d** | 32 | 0.2412 🏆 | 0.5036 | N/A | N/A |
| **mono_64d** | 64 | 0.0627 | 0.4822 | N/A | N/A |
| **mono_128d** | 128 | 0.0098 | 0.4702 | N/A | N/A |
| **aligned_32d** | 32 | 0.2412 | 0.4975 | 0.0596 | 0.3311 |
| **aligned_64d** | 64 | 0.0627 | 0.4601 | 0.0861 | 0.4702 |
| **aligned_128d** | 128 | 0.0098 | 0.4781 | 0.1325 | 0.5033 |

### Key Findings

- **Best Isotropy:** mono_32d with 0.2412 (more uniform distribution)
- **Semantic Density:** Average pairwise similarity of 0.4820. Lower values indicate better semantic separation.
- **Alignment Quality:** Aligned models achieve up to 13.2% R@1 in cross-lingual retrieval.
- **Recommendation:** 128d aligned for best cross-lingual performance

---
## 6.  Morphological Analysis (Experimental)

This section presents an automated morphological analysis derived from the statistical divergence between word-level and subword-level models. By analyzing where subword predictability spikes and where word-level coverage fails, we can infer linguistic structures without supervised data.

### 6.1 Productivity & Complexity

| Metric | Value | Interpretation | Recommendation |
|--------|-------|----------------|----------------|
| Productivity Index | **5.000** | High morphological productivity | Reliable analysis |
| Idiomaticity Gap | **1.531** | High formulaic/idiomatic content | - |

### 6.2 Affix Inventory (Productive Units)

These are the most productive prefixes and suffixes identified by sampling the vocabulary for global substitutability patterns. A unit is considered an affix if stripping it leaves a valid stem that appears in other contexts.

#### Productive Prefixes
| Prefix | Examples |
|--------|----------|

#### Productive Suffixes
| Suffix | Examples |
|--------|----------|
| `-ꮝꮧ` | ꭴꮒꭹꮝꮧ, ꮞꮧᏻꮝꮧ, ꭰꮣꮿꮝꮧ |

### 6.3 Bound Stems (Lexical Roots)

Bound stems are high-frequency subword units that are semantically cohesive but rarely appear as standalone words. These often correspond to the 'core' of a word that requires inflection or derivation to be valid.

*No significant bound stems detected.*


### 6.4 Affix Compatibility (Co-occurrence)

This table shows which prefixes and suffixes most frequently co-occur on the same stems, revealing the 'stacking' rules of the language's morphology.

*No significant affix co-occurrences detected.*


### 6.5 Recursive Morpheme Segmentation

Using **Recursive Hierarchical Substitutability**, we decompose complex words into their constituent morphemes. This approach handles nested affixes (e.g., `prefix-prefix-root-suffix`).

| Word | Suggested Split | Confidence | Stem |
|------|-----------------|------------|------|
| ꭰᏸꮅꮧꭶꮃꮻꭲꮝꮧ | **`ꭰᏸꮅꮧꭶꮃꮻꭲ-ꮝꮧ`** | 1.5 | `ꭰᏸꮅꮧꭶꮃꮻꭲ` |
| ꮒꭶꮅꮝꮧꮝꭸꮝꮧ | **`ꮒꭶꮅꮝꮧꮝꭸ-ꮝꮧ`** | 1.5 | `ꮒꭶꮅꮝꮧꮝꭸ` |

### 6.6 Linguistic Interpretation

> **Automated Insight:**
The language Cherokee shows high morphological productivity. The subword models are significantly more efficient than word models, suggesting a rich system of affixation or compounding.

> **Note on Idiomaticity:** The high Idiomaticity Gap suggests a large number of frequent multi-word expressions or formulaic sequences that are statistically distinct from their component parts.

---
## 7. Summary & Recommendations

![Performance Dashboard](visualizations/performance_dashboard.png)

### Production Recommendations

| Component | Recommended | Rationale |
|-----------|-------------|-----------|
| Tokenizer | **32k BPE** | Best compression (3.55x) |
| N-gram | **2-gram** | Lowest perplexity (151) |
| Markov | **Context-4** | Highest predictability (98.6%) |
| 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},
  doi = {10.5281/zenodo.18073153},
  publisher = {Zenodo},
  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)
- 🤝 Sponsor: [Featherless AI](https://featherless.ai)
---
*Generated by Wikilangs Models Pipeline*

*Report Date: 2026-01-03 20:28:09*