language: ary
language_name: Moroccan Arabic
language_family: arabic
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-arabic
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: 4.171
- name: best_isotropy
type: isotropy
value: 0.8284
- name: vocabulary_size
type: vocab
value: 0
generated: 2026-01-03T00:00:00.000Z
Moroccan Arabic - Wikilangs Models
Comprehensive Research Report & Full Ablation Study
This repository contains NLP models trained and evaluated by Wikilangs, specifically on Moroccan Arabic 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
Analysis and Evaluation
- 1. Tokenizer Evaluation
- 2. N-gram Model Evaluation
- 3. Markov Chain Evaluation
- 4. Vocabulary Analysis
- 5. Word Embeddings Evaluation
- 6. Morphological Analysis (Experimental)
- 7. Summary & Recommendations
- Metrics Glossary
- Visualizations Index
1. Tokenizer Evaluation
Results
| Vocab Size | Compression | Avg Token Len | UNK Rate | Total Tokens |
|---|---|---|---|---|
| 8k | 3.480x | 3.48 | 0.0910% | 300,099 |
| 16k | 3.753x | 3.76 | 0.0981% | 278,271 |
| 32k | 3.983x | 3.99 | 0.1041% | 262,209 |
| 64k | 4.171x 🏆 | 4.18 | 0.1090% | 250,397 |
Tokenization Examples
Below are sample sentences tokenized with each vocabulary size:
Sample 1: هادي صفحة د التوضيح، كلمة بركان يمكن يكونو عندها هاد لمعاني: بْرْكان: مدينة مغري...
| Vocab | Tokens | Count |
|---|---|---|
| 8k | ▁هادي ▁صفحة ▁د ▁التوضيح ، ▁كلمة ▁بركان ▁يمكن ▁يكونو ▁عندها ... (+23 more) |
33 |
| 16k | ▁هادي ▁صفحة ▁د ▁التوضيح ، ▁كلمة ▁بركان ▁يمكن ▁يكونو ▁عندها ... (+21 more) |
31 |
| 32k | ▁هادي ▁صفحة ▁د ▁التوضيح ، ▁كلمة ▁بركان ▁يمكن ▁يكونو ▁عندها ... (+19 more) |
29 |
| 64k | ▁هادي ▁صفحة ▁د ▁التوضيح ، ▁كلمة ▁بركان ▁يمكن ▁يكونو ▁عندها ... (+18 more) |
28 |
Sample 2: لْفزضاض ؤلا أفزضاض (سمية لعلمية Microcosmus sabatieri) حيوان لاسنسولي كيعيش ف لب...
| Vocab | Tokens | Count |
|---|---|---|
| 8k | ▁لْ ف ز ضاض ▁ؤلا ▁أف ز ضاض ▁( سمية ... (+31 more) |
41 |
| 16k | ▁لْ ف ز ضاض ▁ؤلا ▁أف ز ضاض ▁( سمية ... (+28 more) |
38 |
| 32k | ▁لْف ز ضاض ▁ؤلا ▁أف ز ضاض ▁( سمية ▁لعلمية ... (+25 more) |
35 |
| 64k | ▁لْف زضاض ▁ؤلا ▁أف زضاض ▁( سمية ▁لعلمية ▁microcos mus ... (+17 more) |
27 |
Sample 3: نيلز أبراهام لانݣليت (مزيود ف 9 يوليوز - مات ف 30 مارس هوّا عالم د شّيمي سويدي. ...
| Vocab | Tokens | Count |
|---|---|---|
| 8k | ▁نيل ز ▁أب راهام ▁ل انݣ ليت ▁( مزيود ▁ف ... (+19 more) |
29 |
| 16k | ▁نيل ز ▁أبراهام ▁ل انݣ ليت ▁( مزيود ▁ف ▁ ... (+16 more) |
26 |
| 32k | ▁نيلز ▁أبراهام ▁لانݣ ليت ▁( مزيود ▁ف ▁ 9 ▁يوليوز ... (+14 more) |
24 |
| 64k | ▁نيلز ▁أبراهام ▁لانݣليت ▁( مزيود ▁ف ▁ 9 ▁يوليوز ▁- ... (+13 more) |
23 |
Key Findings
- Best Compression: 64k achieves 4.171x compression
- Lowest UNK Rate: 8k with 0.0910% 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
Results
| N-gram | Variant | Perplexity | Entropy | Unique N-grams | Top-100 Coverage | Top-1000 Coverage |
|---|---|---|---|---|---|---|
| 2-gram | Word | 7,228 | 12.82 | 39,512 | 23.0% | 50.8% |
| 2-gram | Subword | 424 🏆 | 8.73 | 5,903 | 58.0% | 96.4% |
| 3-gram | Word | 5,655 | 12.47 | 43,555 | 27.5% | 57.1% |
| 3-gram | Subword | 3,784 | 11.89 | 44,651 | 23.1% | 60.7% |
| 4-gram | Word | 7,985 | 12.96 | 70,559 | 27.5% | 53.6% |
| 4-gram | Subword | 20,064 | 14.29 | 220,807 | 12.0% | 36.0% |
| 5-gram | Word | 7,565 | 12.89 | 58,964 | 28.5% | 52.9% |
| 5-gram | Subword | 62,379 | 15.93 | 527,725 | 7.3% | 25.0% |
Top 5 N-grams by Size
2-grams (Word):
| Rank | N-gram | Count |
|---|---|---|
| 1 | واصلة ل |
8,540 |
| 2 | نسبة د |
7,170 |
| 3 | ف لمغريب |
6,305 |
| 4 | ف إقليم |
6,018 |
| 5 | ف نسبة |
4,265 |
3-grams (Word):
| Rank | N-gram | Count |
|---|---|---|
| 1 | ف نسبة د |
4,264 |
| 2 | فيها مصدر و |
3,236 |
| 3 | و نسبة د |
2,894 |
| 4 | مصدر و بايت |
2,856 |
| 5 | اللي خدامين ف |
2,760 |
4-grams (Word):
| Rank | N-gram | Count |
|---|---|---|
| 1 | فيها مصدر و بايت |
2,856 |
| 2 | نسبة نّاس اللي خدامين |
2,705 |
| 3 | نّاس اللي خدامين ف |
2,594 |
| 4 | على حساب لإحصاء الرسمي |
2,501 |
| 5 | حساب لإحصاء الرسمي د |
2,500 |
5-grams (Word):
| Rank | N-gram | Count |
|---|---|---|
| 1 | نسبة نّاس اللي خدامين ف |
2,593 |
| 2 | ف لمغريب هاد دّوار كينتامي |
2,500 |
| 3 | هاد دّوار كينتامي ل مشيخة |
2,500 |
| 4 | لمغريب هاد دّوار كينتامي ل |
2,500 |
| 5 | حساب لإحصاء الرسمي د عام |
2,500 |
2-grams (Subword):
| Rank | N-gram | Count |
|---|---|---|
| 1 | ا ل |
347,466 |
| 2 | _ ل |
278,371 |
| 3 | ة _ |
229,442 |
| 4 | _ ا |
220,960 |
| 5 | _ م |
156,801 |
3-grams (Subword):
| Rank | N-gram | Count |
|---|---|---|
| 1 | _ ا ل |
216,048 |
| 2 | _ ف _ |
83,146 |
| 3 | ا ت _ |
63,800 |
| 4 | ي ة _ |
60,271 |
| 5 | _ د _ |
59,563 |
4-grams (Subword):
| Rank | N-gram | Count |
|---|---|---|
| 1 | _ د ي ا |
47,798 |
| 2 | د ي ا ل |
47,559 |
| 3 | ي ا ل _ |
33,039 |
| 4 | د _ ا ل |
32,831 |
| 5 | _ م ن _ |
28,909 |
5-grams (Subword):
| Rank | N-gram | Count |
|---|---|---|
| 1 | _ د ي ا ل |
47,427 |
| 2 | د ي ا ل _ |
32,608 |
| 3 | _ ع ل ى _ |
19,473 |
| 4 | _ ا ل ل ي |
18,967 |
| 5 | ا ل ل ي _ |
18,744 |
Key Findings
- Best Perplexity: 2-gram (subword) with 424
- Entropy Trend: Decreases with larger n-grams (more predictable)
- Coverage: Top-1000 patterns cover ~25% of corpus
- Recommendation: 4-gram or 5-gram for best predictive performance
3. Markov Chain Evaluation
Results
| Context | Variant | Avg Entropy | Perplexity | Branching Factor | Unique Contexts | Predictability |
|---|---|---|---|---|---|---|
| 1 | Word | 0.8561 | 1.810 | 5.38 | 178,865 | 14.4% |
| 1 | Subword | 1.1236 | 2.179 | 8.36 | 2,156 | 0.0% |
| 2 | Word | 0.2259 | 1.169 | 1.49 | 962,233 | 77.4% |
| 2 | Subword | 0.8160 | 1.761 | 5.10 | 18,029 | 18.4% |
| 3 | Word | 0.0618 | 1.044 | 1.10 | 1,431,084 | 93.8% |
| 3 | Subword | 0.8022 | 1.744 | 4.13 | 91,858 | 19.8% |
| 4 | Word | 0.0208 🏆 | 1.015 | 1.04 | 1,574,083 | 97.9% |
| 4 | Subword | 0.6604 | 1.581 | 2.86 | 379,445 | 34.0% |
Generated Text Samples (Word-based)
Below are text samples generated from each word-based Markov chain model:
Context Size 1:
ف لمغريب فيها 5 463 462 461 كم من غير ب شبه منقّر مكررعبد المسيح فيو أداب روسيا ف لمغريب ف وقت مابين اللغات الرسمية ديال حيزب لإستقلال تا سينيما ليهاد الناس فليبيا اكتشفو أنه يتقتل ولكن بقات كتلعب فالتيران ديال هاد الريحلة معا لمونتاخاب و
Context Size 2:
واصلة ل 98 6 و عدد لفاميلات تزاد ب 81 6 و نسبة د الناس و لمحيطنسبة د الشوماج واصلة ل 21 12 نوطات مصادر ف لمغريب جّبل معروف عند الصامويين حتال ليومف لمغريب هاد دّوار كينتامي ل مشيخة سدي حمد الدغوغي لي كتضم 14 د دّواور لعاداد د
Context Size 3:
ف نسبة د التسكويل واصلة ل 91 89 و نسبة د الشوماج واصلة ل 7 6 و لخصوبةفيها مصدر و بايت زادهوم داريجابوت حيين مغاربا د لقرن 21 مغاربا مغاربا فيها مصدر و بايت زادهومو نسبة د لأمية واصلة ل 53 4 و نسبة د لأمية واصلة ل 92 5 و نسبة
Context Size 4:
نسبة نّاس اللي خدامين ف دّولة ولا لبيطاليين اللي سبق ليهوم خدمو 44 3 نسبة نّاس اللي خدامين فنّاس اللي خدامين ف لپريڤي ولا لبيطاليين اللي سبق ليهوم مصادر الدار البيضاء سطات قروية ف إقليم سطات ق...على حساب لإحصاء الرسمي د عام إحصائيات إحصائيات عامة عدد السكان ديال أورسفان نقص ب 30 7 و عدد
Generated Text Samples (Subword-based)
Below are text samples generated from each subword-based Markov chain model:
Context Size 1:
_دّرى_لجالب_لتالعاكترن_لعاميلة_ن_لت_پرومدي_و_ماتم
Context Size 2:
الرجل_بين_ماعة_لخ_لكينو_العرفوقعوهة_27_نت،_خري_د_لج
Context Size 3:
_الروس_و_هي_ماية_ك_ف_موقريب._الدفاييات_ف_البالشخصياتول
Context Size 4:
_ديالو._ميامينش_و_تديال_أسباب_الغرب_6_يال_تعرّض_للحزب_الوه
Key Findings
- Best Predictability: Context-4 (word) with 97.9% predictability
- Branching Factor: Decreases with context size (more deterministic)
- Memory Trade-off: Larger contexts require more storage (379,445 contexts)
- Recommendation: Context-3 or Context-4 for text generation
4. Vocabulary Analysis
Statistics
| Metric | Value |
|---|---|
| Vocabulary Size | 78,779 |
| Total Tokens | 2,032,841 |
| Mean Frequency | 25.80 |
| Median Frequency | 4 |
| Frequency Std Dev | 515.92 |
Most Common Words
| Rank | Word | Frequency |
|---|---|---|
| 1 | ف | 83,458 |
| 2 | و | 59,829 |
| 3 | د | 59,731 |
| 4 | ديال | 32,565 |
| 5 | من | 29,236 |
| 6 | ل | 23,572 |
| 7 | على | 19,570 |
| 8 | لي | 18,402 |
| 9 | اللي | 17,442 |
| 10 | ب | 17,233 |
Least Common Words (from vocabulary)
| Rank | Word | Frequency |
|---|---|---|
| 1 | بوفوار | 2 |
| 2 | بيتسي | 2 |
| 3 | وصانعي | 2 |
| 4 | وأهميتها | 2 |
| 5 | بورديو | 2 |
| 6 | بلومر | 2 |
| 7 | مقترحة | 2 |
| 8 | anchor | 2 |
| 9 | بعصبة | 2 |
| 10 | ماڭي | 2 |
Zipf's Law Analysis
| Metric | Value |
|---|---|
| Zipf Coefficient | 1.0213 |
| R² (Goodness of Fit) | 0.998918 |
| Adherence Quality | excellent |
Coverage Analysis
| Top N Words | Coverage |
|---|---|
| Top 100 | 38.6% |
| Top 1,000 | 62.9% |
| Top 5,000 | 77.8% |
| Top 10,000 | 84.2% |
Key Findings
- Zipf Compliance: R²=0.9989 indicates excellent adherence to Zipf's law
- High Frequency Dominance: Top 100 words cover 38.6% of corpus
- Long Tail: 68,779 words needed for remaining 15.8% coverage
5. Word Embeddings Evaluation
5.1 Cross-Lingual Alignment
5.2 Model Comparison
| Model | Dimension | Isotropy | Semantic Density | Alignment R@1 | Alignment R@10 |
|---|---|---|---|---|---|
| mono_32d | 32 | 0.8284 🏆 | 0.3330 | N/A | N/A |
| mono_64d | 64 | 0.8181 | 0.2588 | N/A | N/A |
| mono_128d | 128 | 0.7036 | 0.2093 | N/A | N/A |
| aligned_32d | 32 | 0.8284 | 0.3345 | 0.0180 | 0.1360 |
| aligned_64d | 64 | 0.8181 | 0.2550 | 0.0380 | 0.1760 |
| aligned_128d | 128 | 0.7036 | 0.2072 | 0.0620 | 0.2760 |
Key Findings
- Best Isotropy: mono_32d with 0.8284 (more uniform distribution)
- Semantic Density: Average pairwise similarity of 0.2663. Lower values indicate better semantic separation.
- Alignment Quality: Aligned models achieve up to 6.2% 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 | 1.114 | 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 |
|---|---|
-ال |
الأمني, اللحظة, الفيرمات |
-لم |
لمتعصبين, لمحافض, لمونضامة |
-كا |
كاتدير, كايتحلو, كايقممو |
Productive Suffixes
| Suffix | Examples |
|---|---|
-ة |
سميّة, رقصة, اللحظة |
-ات |
سطراتيجيات, الفيرمات, لحتيفالات |
-ية |
الشرقية, اللاجنسية, ولوسطانية |
-ين |
لمتعصبين, ثنين, لمالحين |
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.
| Stem | Cohesion | Substitutability | Examples |
|---|---|---|---|
انية |
1.80x | 68 contexts | غانية, ثانية, سانية |
اللو |
1.74x | 61 contexts | اللوه, اللور, اللول |
الات |
1.71x | 65 contexts | تالات, حالات, صالات |
جماع |
1.90x | 38 contexts | جماعي, تجماع, إجماع |
النا |
1.63x | 63 contexts | الناي, النار, الناس |
لمغر |
1.92x | 30 contexts | لمغرب, لمغربب, للمغرب |
إحصا |
2.13x | 17 contexts | إحصاء, لإحصا, إحصائي |
مغري |
2.08x | 18 contexts | مغريب, مغرية, مغريبي |
حصاء |
2.24x | 14 contexts | إحصاء, لإحصاء, ليحصاء |
دهوم |
2.14x | 16 contexts | ضدهوم, يردهوم, زادهوم |
قليم |
2.06x | 17 contexts | فقليم, اقليم, إقليم |
لجوا |
1.77x | 26 contexts | لجواب, لجواد, الجوا |
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.
| Prefix | Suffix | Frequency | Examples |
|---|---|---|---|
-ال |
-ة |
280 words | الراكوبة, العمدة |
-ال |
-ات |
163 words | الشلالات, العبرات |
-ال |
-ية |
152 words | الزراعية, الطباشيرية |
-ال |
-ين |
76 words | الموحدين, الاثنين |
-لم |
-ة |
66 words | لمملكة, لمُحمدية |
-لم |
-ين |
45 words | لموناضيلين, لمعتقلين |
-لم |
-ات |
25 words | لمونضّامات, لممرات |
-لم |
-ية |
21 words | لمُحمدية, لمراكشية |
-كا |
-ين |
2 words | كايسين, كاتبين |
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 |
|---|---|---|---|
| التوجيهات | ال-توجيه-ات |
6.0 | توجيه |
| الصومالية | ال-صومال-ية |
6.0 | صومال |
| الپاكستانية | ال-پاكستان-ية |
6.0 | پاكستان |
| الدوّازات | ال-دوّاز-ات |
6.0 | دوّاز |
| الصالونات | ال-صالون-ات |
6.0 | صالون |
| التعبيرية | ال-تعبير-ية |
6.0 | تعبير |
| الانقلابية | ال-انقلاب-ية |
6.0 | انقلاب |
| لمنقارضين | لم-نقارض-ين |
6.0 | نقارض |
| التقليديين | ال-تقليدي-ين |
6.0 | تقليدي |
| لمنتاشرين | لم-نتاشر-ين |
6.0 | نتاشر |
| الماكينات | ال-ماكين-ات |
6.0 | ماكين |
| البرونزية | ال-برونز-ية |
6.0 | برونز |
| التكوينية | ال-تكوين-ية |
6.0 | تكوين |
| التعليمية | ال-تعليم-ية |
6.0 | تعليم |
| التلفزيونية | ال-تلفزيون-ية |
6.0 | تلفزيون |
6.6 Linguistic Interpretation
Automated Insight: The language Moroccan Arabic 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
Production Recommendations
| Component | Recommended | Rationale |
|---|---|---|
| Tokenizer | 64k BPE | Best compression (4.17x) |
| N-gram | 2-gram | Lowest perplexity (424) |
| Markov | Context-4 | Highest predictability (97.9%) |
| 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
- Compare within model families: Metrics are most meaningful when comparing models of the same type (e.g., 8k vs 64k tokenizer).
- Consider trade-offs: Better performance on one metric often comes at the cost of another (e.g., compression vs. OOV rate).
- Context matters: Optimal values depend on downstream tasks. Text generation may prioritize different metrics than classification.
- Corpus influence: All metrics are influenced by corpus characteristics. Wikipedia text differs from social media or literature.
- 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 - a monthly snapshot of Wikipedia articles across 300+ languages.
Project
A project by Wikilangs - Open-source NLP models for every Wikipedia language.
Maintainer
Citation
If you use these models in your research, please cite:
@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
- 🤗 Models: huggingface.co/wikilangs
- 📊 Data: wikipedia-monthly
- 👤 Author: Omar Kamali
- 🤝 Sponsor: Featherless AI
Generated by Wikilangs Models Pipeline
Report Date: 2026-01-03 16:42:17



















