Yoruba - Wikilangs Models
Comprehensive Research Report & Full Ablation Study
This repository contains NLP models trained and evaluated by Wikilangs, specifically on Yoruba Wikipedia data. We analyze tokenizers, n-gram models, Markov chains, vocabulary statistics, and word embeddings.
π 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 | 3.147x | 3.15 | 0.2917% | 765,613 |
| 16k | 3.396x | 3.40 | 0.3147% | 709,643 |
| 32k | 3.597x | 3.60 | 0.3334% | 669,837 |
| 64k | 3.758x π | 3.76 | 0.3482% | 641,232 |
Tokenization Examples
Below are sample sentences tokenized with each vocabulary size:
Sample 1: jαΊΉΜ plΓ‘nαΊΉΜtΓ¬ kΓ©kerΓ© nΓ ibi Γ¬gbΓ jΓ‘ Γ‘stαΊΉΜrα»ΜΓ¬dΓ¬. Itokasi Γ‘stαΊΉΜrα»ΜΓ¬dΓ¬
| Vocab | Tokens | Count |
|---|---|---|
| 8k | βjαΊΉΜ βplΓ‘nαΊΉΜtΓ¬ βkΓ©kerΓ© βnΓ βibi βΓ¬gbΓ jΓ‘ βΓ‘stαΊΉΜrα»ΜΓ¬dΓ¬ . βitokasi βΓ‘stαΊΉΜrα»ΜΓ¬dΓ¬ |
10 |
| 16k | βjαΊΉΜ βplΓ‘nαΊΉΜtΓ¬ βkΓ©kerΓ© βnΓ βibi βΓ¬gbΓ jΓ‘ βΓ‘stαΊΉΜrα»ΜΓ¬dΓ¬ . βitokasi βΓ‘stαΊΉΜrα»ΜΓ¬dΓ¬ |
10 |
| 32k | βjαΊΉΜ βplΓ‘nαΊΉΜtΓ¬ βkΓ©kerΓ© βnΓ βibi βΓ¬gbΓ jΓ‘ βΓ‘stαΊΉΜrα»ΜΓ¬dΓ¬ . βitokasi βΓ‘stαΊΉΜrα»ΜΓ¬dΓ¬ |
10 |
| 64k | βjαΊΉΜ βplΓ‘nαΊΉΜtΓ¬ βkΓ©kerΓ© βnΓ βibi βΓ¬gbΓ jΓ‘ βΓ‘stαΊΉΜrα»ΜΓ¬dΓ¬ . βitokasi βΓ‘stαΊΉΜrα»ΜΓ¬dΓ¬ |
10 |
Sample 2: je Aare orile-ede Haiti tele. Itokasi ΓΓ rαΊΉ ilαΊΉΜ HΓ ΓtΓ¬
| Vocab | Tokens | Count |
|---|---|---|
| 8k | βje βaare βorile - ede βhaiti βtele . βitokasi βΓ Γ rαΊΉ ... (+2 more) |
12 |
| 16k | βje βaare βorile - ede βhaiti βtele . βitokasi βΓ Γ rαΊΉ ... (+2 more) |
12 |
| 32k | βje βaare βorile - ede βhaiti βtele . βitokasi βΓ Γ rαΊΉ ... (+2 more) |
12 |
| 64k | βje βaare βorile - ede βhaiti βtele . βitokasi βΓ Γ rαΊΉ ... (+2 more) |
12 |
Sample 3: jαΊΉΜ plΓ‘nαΊΉΜtΓ¬ kΓ©kerΓ© nΓ ibi Γ¬gbΓ jΓ‘ Γ‘stαΊΉΜrα»ΜΓ¬dΓ¬. Itokasi
| Vocab | Tokens | Count |
|---|---|---|
| 8k | βjαΊΉΜ βplΓ‘nαΊΉΜtΓ¬ βkΓ©kerΓ© βnΓ βibi βΓ¬gbΓ jΓ‘ βΓ‘stαΊΉΜrα»ΜΓ¬dΓ¬ . βitokasi |
9 |
| 16k | βjαΊΉΜ βplΓ‘nαΊΉΜtΓ¬ βkΓ©kerΓ© βnΓ βibi βΓ¬gbΓ jΓ‘ βΓ‘stαΊΉΜrα»ΜΓ¬dΓ¬ . βitokasi |
9 |
| 32k | βjαΊΉΜ βplΓ‘nαΊΉΜtΓ¬ βkΓ©kerΓ© βnΓ βibi βΓ¬gbΓ jΓ‘ βΓ‘stαΊΉΜrα»ΜΓ¬dΓ¬ . βitokasi |
9 |
| 64k | βjαΊΉΜ βplΓ‘nαΊΉΜtΓ¬ βkΓ©kerΓ© βnΓ βibi βΓ¬gbΓ jΓ‘ βΓ‘stαΊΉΜrα»ΜΓ¬dΓ¬ . βitokasi |
9 |
Key Findings
- Best Compression: 64k achieves 3.758x compression
- Lowest UNK Rate: 8k with 0.2917% 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 | 15,512 | 13.92 | 75,926 | 18.0% | 37.6% |
| 2-gram | Subword | 467 π | 8.87 | 6,012 | 53.2% | 97.2% |
| 3-gram | Word | 29,860 | 14.87 | 120,521 | 14.8% | 28.4% |
| 3-gram | Subword | 4,102 | 12.00 | 51,496 | 19.8% | 59.0% |
| 4-gram | Word | 59,917 | 15.87 | 214,920 | 13.7% | 22.5% |
| 4-gram | Subword | 22,011 | 14.43 | 265,494 | 12.0% | 33.3% |
| 5-gram | Word | 40,150 | 15.29 | 156,085 | 16.5% | 24.8% |
| 5-gram | Subword | 73,071 | 16.16 | 699,133 | 9.2% | 23.4% |
Top 5 N-grams by Size
2-grams (Word):
| Rank | N-gram | Count |
|---|---|---|
| 1 | tΓ Γ³ |
19,475 |
| 2 | nΓ ibi |
14,923 |
| 3 | kΓ©kerΓ© nΓ |
14,762 |
| 4 | ibi Γ¬gbΓ jΓ‘ |
14,739 |
| 5 | Γ¬gbΓ jΓ‘ Γ‘stαΊΉΜrα»ΜΓ¬dΓ¬ |
14,725 |
3-grams (Word):
| Rank | N-gram | Count |
|---|---|---|
| 1 | nΓ ibi Γ¬gbΓ jΓ‘ |
14,739 |
| 2 | kΓ©kerΓ© nΓ ibi |
14,738 |
| 3 | ibi Γ¬gbΓ jΓ‘ Γ‘stαΊΉΜrα»ΜΓ¬dΓ¬ |
14,725 |
| 4 | jαΊΉΜ plΓ‘nαΊΉΜtΓ¬ kΓ©kerΓ© |
14,688 |
| 5 | plΓ‘nαΊΉΜtΓ¬ kΓ©kerΓ© nΓ |
14,688 |
4-grams (Word):
| Rank | N-gram | Count |
|---|---|---|
| 1 | kΓ©kerΓ© nΓ ibi Γ¬gbΓ jΓ‘ |
14,738 |
| 2 | nΓ ibi Γ¬gbΓ jΓ‘ Γ‘stαΊΉΜrα»ΜΓ¬dΓ¬ |
14,725 |
| 3 | plΓ‘nαΊΉΜtΓ¬ kΓ©kerΓ© nΓ ibi |
14,688 |
| 4 | jαΊΉΜ plΓ‘nαΊΉΜtΓ¬ kΓ©kerΓ© nΓ |
14,688 |
| 5 | ibi Γ¬gbΓ jΓ‘ Γ‘stαΊΉΜrα»ΜΓ¬dΓ¬ itokasi |
14,641 |
5-grams (Word):
| Rank | N-gram | Count |
|---|---|---|
| 1 | kΓ©kerΓ© nΓ ibi Γ¬gbΓ jΓ‘ Γ‘stαΊΉΜrα»ΜΓ¬dΓ¬ |
14,724 |
| 2 | plΓ‘nαΊΉΜtΓ¬ kΓ©kerΓ© nΓ ibi Γ¬gbΓ jΓ‘ |
14,688 |
| 3 | jαΊΉΜ plΓ‘nαΊΉΜtΓ¬ kΓ©kerΓ© nΓ ibi |
14,688 |
| 4 | nΓ ibi Γ¬gbΓ jΓ‘ Γ‘stαΊΉΜrα»ΜΓ¬dΓ¬ itokasi |
14,641 |
| 5 | ibi Γ¬gbΓ jΓ‘ Γ‘stαΊΉΜrα»ΜΓ¬dΓ¬ itokasi Γ‘stαΊΉΜrα»ΜΓ¬dΓ¬ |
13,854 |
2-grams (Subword):
| Rank | N-gram | Count |
|---|---|---|
| 1 | n _ |
450,694 |
| 2 | i _ |
405,534 |
| 3 | _ a |
300,083 |
| 4 | _ n |
283,323 |
| 5 | _ t |
247,960 |
3-grams (Subword):
| Rank | N-gram | Count |
|---|---|---|
| 1 | t i _ |
153,979 |
| 2 | _ n Γ |
105,250 |
| 3 | _ n i |
102,296 |
| 4 | w α» n |
90,977 |
| 5 | α» n _ |
90,343 |
4-grams (Subword):
| Rank | N-gram | Count |
|---|---|---|
| 1 | w α» n _ |
88,162 |
| 2 | _ n Γ _ |
74,812 |
| 3 | _ n i _ |
74,453 |
| 4 | _ t i _ |
69,707 |
| 5 | _ t Γ _ |
50,988 |
5-grams (Subword):
| Rank | N-gram | Count |
|---|---|---|
| 1 | Γ w α» n _ |
46,754 |
| 2 | _ Γ w α» n |
46,122 |
| 3 | a w α» n _ |
30,885 |
| 4 | _ a w α» n |
30,498 |
| 5 | t αΊΉΜ r α»Μ Γ¬ |
28,695 |
Key Findings
- Best Perplexity: 2-gram (subword) with 467
- Entropy Trend: Decreases with larger n-grams (more predictable)
- Coverage: Top-1000 patterns cover ~23% 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 | 0.8773 | 1.837 | 7.00 | 179,072 | 12.3% |
| 1 | Subword | 0.8392 | 1.789 | 6.66 | 2,526 | 16.1% |
| 2 | Word | 0.2998 | 1.231 | 1.81 | 1,250,964 | 70.0% |
| 2 | Subword | 0.8984 | 1.864 | 6.12 | 16,794 | 10.2% |
| 3 | Word | 0.1182 | 1.085 | 1.23 | 2,252,885 | 88.2% |
| 3 | Subword | 0.8307 | 1.779 | 4.43 | 102,698 | 16.9% |
| 4 | Word | 0.0490 π | 1.035 | 1.08 | 2,755,002 | 95.1% |
| 4 | Subword | 0.6691 | 1.590 | 3.04 | 454,606 | 33.1% |
Generated Text Samples (Word-based)
Below are text samples generated from each word-based Markov chain model:
Context Size 1:
ni ojuiyipo re unje lilo ede nedalandi Γ³ fara jα» αΉ£e nΓ Γ²rΓ¬αΉ£Γ nΓ ibi Γ¬gbΓ jΓ‘nΓ bαΊΉΜ mΓ a gbα»Μ ni Γ wα»n αΊΉni pΓ© ayΓ© to lower alpha capture and sunti Γ wα»n Γ¬rΓ²yΓ¬n Γ²fegΓ¨ tΓ Γ³ lα» ti o tun a kìà ṣe Γ¬wΓ‘dìà tΓ³ wΓ‘
Context Size 2:
tΓ Γ³ gbΓ²Γ²rΓ² jΓΉlα» nΓ orΓlαΊΉΜ Γ¨dΓ¨ nΓ ΓjΓrΓ¬a α»jα»Μ Γ¬bΓ april 28 jαΊΉΜ gbajΓΊmα»Μ fΓΊn Γ wα»Μ dΓΊdΓΊnΓ ibi Γ¬gbΓ jΓ‘ Γ‘stαΊΉΜrα»ΜΓ¬dΓ¬ itokasi Γ‘stαΊΉΜrα»ΜΓ¬dΓ¬ vec lista de zachiakΓ©kerΓ© nΓ ibi Γ¬gbΓ jΓ‘ Γ‘stαΊΉΜrα»ΜΓ¬dΓ¬ itokasi Γ‘stαΊΉΜrα»ΜΓ¬dΓ¬ vec lista de yebes
Context Size 3:
nΓ ibi Γ¬gbΓ jΓ‘ Γ‘stαΊΉΜrα»ΜΓ¬dΓ¬ itokasi Γ‘stαΊΉΜrα»ΜΓ¬dΓ¬ vec lista de adriakΓ©kerΓ© nΓ ibi Γ¬gbΓ jΓ‘ Γ‘stαΊΉΜrα»ΜΓ¬dΓ¬ itokasi Γ‘stαΊΉΜrα»ΜΓ¬dΓ¬ vec lista de aΓ«nnaibi Γ¬gbΓ jΓ‘ Γ‘stαΊΉΜrα»ΜΓ¬dΓ¬ itokasi Γ‘stαΊΉΜrα»ΜΓ¬dΓ¬ vec lista de megaira
Context Size 4:
kΓ©kerΓ© nΓ ibi Γ¬gbΓ jΓ‘ Γ‘stαΊΉΜrα»ΜΓ¬dΓ¬ itokasi Γ‘stαΊΉΜrα»ΜΓ¬dΓ¬ vec lista de zachianΓ ibi Γ¬gbΓ jΓ‘ Γ‘stαΊΉΜrα»ΜΓ¬dΓ¬ itokasi Γ‘stαΊΉΜrα»ΜΓ¬dΓ¬ vec lista de tolkienplΓ‘nαΊΉΜtΓ¬ kΓ©kerΓ© nΓ ibi Γ¬gbΓ jΓ‘ Γ‘sΓtαΊΉΜrα»ΜΓ¬dΓ¬ itokasi Γ‘stαΊΉΜrα»ΜΓ¬dΓ¬
Generated Text Samples (Subword-based)
Below are text samples generated from each subword-based Markov chain model:
Context Size 1:
_ncan_denla_bΓΓ¬di_-arαΊΉΜtuar_Γ Γ n_Γ¬n),_nΓn_aunerda_
Context Size 2:
n_ó_sìnlejì_à tò_ìi_ìgballe_naind_t_africanric_o_unt
Context Size 3:
ti_olΓΉdarΓ_Γ¬mα»Μ_rΓ‘Γ_nΓ_orilαΊΉ_ni_fΓΓ¬mΓΉ_nipinle_kway_jαΊΉΜ_o
Context Size 4:
wα»n_Γ¬tΓ n_Γ¬mα»Μ-αΊΉΜrα»_ti_nΓ_Γ¨dΓ¨_egypt_leade_ni_arΓ‘bΓ¬nrin_wα»Μn_g
Key Findings
- Best Predictability: Context-4 (word) with 95.1% predictability
- Branching Factor: Decreases with context size (more deterministic)
- Memory Trade-off: Larger contexts require more storage (454,606 contexts)
- Recommendation: Context-3 or Context-4 for text generation
4. Vocabulary Analysis
Statistics
| Metric | Value |
|---|---|
| Vocabulary Size | 79,381 |
| Total Tokens | 3,414,288 |
| Mean Frequency | 43.01 |
| Median Frequency | 4 |
| Frequency Std Dev | 725.10 |
Most Common Words
| Rank | Word | Frequency |
|---|---|---|
| 1 | nΓ | 76,550 |
| 2 | ni | 76,509 |
| 3 | ti | 70,538 |
| 4 | tΓ | 52,513 |
| 5 | Γ³ | 47,903 |
| 6 | Γ wα»n | 46,664 |
| 7 | jαΊΉΜ | 35,696 |
| 8 | o | 34,127 |
| 9 | awα»n | 30,834 |
| 10 | Γ‘stαΊΉΜrα»ΜΓ¬dΓ¬ | 28,681 |
Least Common Words (from vocabulary)
| Rank | Word | Frequency |
|---|---|---|
| 1 | shaik | 2 |
| 2 | ntombela | 2 |
| 3 | fayawα» | 2 |
| 4 | millarworld | 2 |
| 5 | ordinating | 2 |
| 6 | akα»yα»yα» | 2 |
| 7 | olΓΉgbΓ lΓ© | 2 |
| 8 | kαΊΉαΊΉαΊΉΜdα»Μgbα»Μn | 2 |
| 9 | Γ¬banilαΊΉΜjαΊΉΜ | 2 |
| 10 | obilor | 2 |
Zipf's Law Analysis
| Metric | Value |
|---|---|
| Zipf Coefficient | 1.1348 |
| RΒ² (Goodness of Fit) | 0.995636 |
| Adherence Quality | excellent |
Coverage Analysis
| Top N Words | Coverage |
|---|---|
| Top 100 | 41.3% |
| Top 1,000 | 67.8% |
| Top 5,000 | 83.9% |
| Top 10,000 | 89.3% |
Key Findings
- Zipf Compliance: RΒ²=0.9956 indicates excellent adherence to Zipf's law
- High Frequency Dominance: Top 100 words cover 41.3% of corpus
- Long Tail: 69,381 words needed for remaining 10.7% 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 | 0.8242 π | 0.3333 | N/A | N/A |
| mono_64d | 64 | 0.8144 | 0.2438 | N/A | N/A |
| mono_128d | 128 | 0.7308 | 0.2103 | N/A | N/A |
| aligned_32d | 32 | 0.8242 | 0.3324 | 0.0980 | 0.4180 |
| aligned_64d | 64 | 0.8144 | 0.2547 | 0.1840 | 0.5340 |
| aligned_128d | 128 | 0.7308 | 0.2109 | 0.2460 | 0.6120 |
Key Findings
- Best Isotropy: mono_32d with 0.8242 (more uniform distribution)
- Semantic Density: Average pairwise similarity of 0.2642. Lower values indicate better semantic separation.
- Alignment Quality: Aligned models achieve up to 24.6% 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 | 0.060 | Low formulaic 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 |
|---|---|
-a |
advocate, abΓ‘yα», akα»bi |
-s |
spainclay, spotlite, susanne |
-i |
itanka, ifiranΕ‘αΊΉ, ilΓ©αΉ£a |
-o |
onαΉ£αΊΉ, ologe, olagbegi |
-k |
kowloon, kobe, kulere |
-m |
mαΊΉnuba, melaye, mathew |
-l |
lÑà rΓ, lαΊΉΜru, leili |
-b |
batman, basemera, bolanle |
Productive Suffixes
| Suffix | Examples |
|---|---|
-n |
α»lα»ΜfΓ gangan, batman, kowloon |
-e |
advocate, tope, helaine |
-s |
exegesis, dionΓ½sios, aspergillus |
-a |
xinhua, mαΊΉnuba, basemera |
-i |
nΓji, akα»bi, akinjobi |
-o |
dioulasso, adugbo, woyo |
-d |
exiled, unsold, spelled |
-on |
kowloon, peterson, suggestion |
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 |
|---|---|---|---|
ment |
2.58x | 41 contexts | moment, foment, mental |
tion |
2.39x | 45 contexts | otiono, notion, action |
vers |
2.40x | 41 contexts | verse, versa, ivers |
atio |
2.30x | 36 contexts | ratio, patios, nation |
pΓnl |
2.90x | 16 contexts | Γ¬pΓnl, Γ¬pΓnle, pΓnlαΊΉΜ |
nter |
2.19x | 40 contexts | enter, inter, hunter |
mber |
2.31x | 28 contexts | ember, amber, timber |
eria |
2.17x | 34 contexts | neria, seria, iberia |
orΓl |
2.57x | 18 contexts | orΓle, orΓlΓ¨, orΓlαΊΉ |
iver |
2.29x | 25 contexts | liver, ivers, river |
nìyà |
2.47x | 19 contexts | nìyà n, ẹnìyà n, enìyà n |
ersi |
2.71x | 13 contexts | persia, persian, persist |
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 |
|---|---|---|---|
-a |
-n |
76 words | apÑìwα»ΜΓ²rΓΉn, amotekun |
-a |
-e |
63 words | affordable, ape |
-a |
-a |
54 words | aurora, ayuba |
-m |
-n |
53 words | mα»Μα»ΜyΓ n, mαΊΉΜtin |
-o |
-n |
52 words | omicron, okon |
-k |
-n |
45 words | kpentomun, kìnnìún |
-o |
-e |
45 words | onirojinle, owaΕbe |
-s |
-s |
42 words | setaleyrodes, seas |
-a |
-s |
40 words | abbreviations, ages |
-o |
-a |
40 words | odambea, okΓΊta |
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 |
|---|---|---|---|
| afamefuna | afamefu-n-a |
7.5 | n |
| telifisonu | telifis-on-u |
7.5 | on |
| wenceslaus | wencesl-a-us |
7.5 | a |
| recognise | recogni-s-e |
7.5 | s |
| housemate | housem-a-te |
7.5 | a |
| palæogene | palæoge-n-e |
7.5 | n |
| chimpanzees | chimpanz-e-es |
7.5 | e |
| berlusconi | berlusc-on-i |
7.5 | on |
| questioned | questi-on-ed |
7.5 | on |
| ailagbara | a-i-lagbara |
7.5 | lagbara |
| ibΓ²mΓ¬ΓrΓ n | i-b-Γ²mΓ¬ΓrΓ n |
6.0 | Γ²mΓ¬ΓrΓ n |
| abyssinian | abyssinia-n |
4.5 | abyssinia |
| Γ¬fα»wα»Μsowα»pα»Μ | Γ¬-fα»wα»Μsowα»pα»Μ |
4.5 | fα»wα»Μsowα»pα»Μ |
| concerted | concert-ed |
4.5 | concert |
| interacts | interact-s |
4.5 | interact |
6.6 Linguistic Interpretation
Automated Insight: The language Yoruba shows high morphological productivity. The subword models are significantly more efficient than word models, suggesting a rich system of affixation or compounding.
7. Summary & Recommendations
Production Recommendations
| Component | Recommended | Rationale |
|---|---|---|
| Tokenizer | 64k BPE | Best compression (3.76x) |
| N-gram | 2-gram | Lowest perplexity (467) |
| Markov | Context-4 | Highest predictability (95.1%) |
| 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) Γ 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.
RΒ² (Coefficient of Determination)
Definition: Measures how well the linear fit explains the frequency-rank relationship. Ranges from 0 to 1.
Intuition: RΒ² near 1.0 means the data closely follows Zipf's law; lower values indicate deviation from expected word frequency patterns.
What to seek: RΒ² > 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
- π Website: wikilangs.org
- π€ Models: huggingface.co/wikilangs
- π Data: wikipedia-monthly
- π€ Author: Omar Kamali
- π€ Sponsor: Featherless AI
Generated by Wikilangs Models Pipeline
Report Date: 2026-01-11 05:59:56



















