language: cy
language_name: Welsh
language_family: celtic_brythonic
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-celtic_brythonic
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: 4.109
- name: best_isotropy
type: isotropy
value: 0.842
- name: vocabulary_size
type: vocab
value: 0
generated: 2026-01-04T00:00:00.000Z
Welsh - Wikilangs Models
Comprehensive Research Report & Full Ablation Study
This repository contains NLP models trained and evaluated by Wikilangs, specifically on Welsh 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 | 3.346x | 3.35 | 0.0427% | 894,556 |
| 16k | 3.678x | 3.68 | 0.0469% | 813,770 |
| 32k | 3.925x | 3.93 | 0.0501% | 762,670 |
| 64k | 4.109x 🏆 | 4.11 | 0.0524% | 728,422 |
Tokenization Examples
Below are sample sentences tokenized with each vocabulary size:
Sample 1: Canwr opera o Ganada oedd Jonathan Stewart Vickers, CC (29 Hydref – 10 Gorffenna...
| Vocab | Tokens | Count |
|---|---|---|
| 8k | ▁canwr ▁opera ▁o ▁ganada ▁oedd ▁jonathan ▁stewart ▁v ick ers ... (+30 more) |
40 |
| 16k | ▁canwr ▁opera ▁o ▁ganada ▁oedd ▁jonathan ▁stewart ▁vick ers , ... (+27 more) |
37 |
| 32k | ▁canwr ▁opera ▁o ▁ganada ▁oedd ▁jonathan ▁stewart ▁vick ers , ... (+26 more) |
36 |
| 64k | ▁canwr ▁opera ▁o ▁ganada ▁oedd ▁jonathan ▁stewart ▁vickers , ▁cc ... (+22 more) |
32 |
Sample 2: Pêl-droediwr o Japan yw (ganed 11 Rhagfyr Tîm Cenedlaethol Tîm cenedlaethol Dole...
| Vocab | Tokens | Count |
|---|---|---|
| 8k | ▁pêl - droediwr ▁o ▁japan ▁yw ▁( ganed ▁ 1 ... (+15 more) |
25 |
| 16k | ▁pêl - droediwr ▁o ▁japan ▁yw ▁( ganed ▁ 1 ... (+15 more) |
25 |
| 32k | ▁pêl - droediwr ▁o ▁japan ▁yw ▁( ganed ▁ 1 ... (+15 more) |
25 |
| 64k | ▁pêl - droediwr ▁o ▁japan ▁yw ▁( ganed ▁ 1 ... (+15 more) |
25 |
Sample 3: Clostridium tetani yw'r bacteria sy'n achosi Tetanws.
| Vocab | Tokens | Count |
|---|---|---|
| 8k | ▁cl ost rid ium ▁t et ani ▁yw ' r ... (+13 more) |
23 |
| 16k | ▁cl ost rid ium ▁t et ani ▁yw ' r ... (+12 more) |
22 |
| 32k | ▁cl ost rid ium ▁tet ani ▁yw ' r ▁bacteria ... (+8 more) |
18 |
| 64k | ▁cl ost rid ium ▁tet ani ▁yw ' r ▁bacteria ... (+8 more) |
18 |
Key Findings
- Best Compression: 64k achieves 4.109x compression
- Lowest UNK Rate: 8k with 0.0427% 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 | 17,960 | 14.13 | 742,720 | 26.5% | 49.5% |
| 2-gram | Subword | 266 🏆 | 8.05 | 14,977 | 67.6% | 99.3% |
| 3-gram | Word | 34,403 | 15.07 | 1,470,847 | 23.6% | 43.7% |
| 3-gram | Subword | 2,056 | 11.01 | 96,402 | 28.1% | 74.0% |
| 4-gram | Word | 58,140 | 15.83 | 2,520,966 | 20.5% | 39.2% |
| 4-gram | Subword | 9,573 | 13.22 | 505,960 | 17.0% | 48.0% |
| 5-gram | Word | 66,270 | 16.02 | 2,303,277 | 18.6% | 36.6% |
| 5-gram | Subword | 29,179 | 14.83 | 1,685,188 | 12.7% | 38.3% |
Top 5 N-grams by Size
2-grams (Word):
| Rank | N-gram | Count |
|---|---|---|
| 1 | unol daleithiau |
486,479 |
| 2 | daleithiau america |
459,399 |
| 3 | y ffilm |
330,346 |
| 4 | y cyfarwyddwr |
255,174 |
| 5 | o ffilmiau |
249,770 |
3-grams (Word):
| Rank | N-gram | Count |
|---|---|---|
| 1 | unol daleithiau america |
447,977 |
| 2 | daleithiau america saesneg |
189,392 |
| 3 | gan y cyfarwyddwr |
147,806 |
| 4 | gan gynnwys y |
143,480 |
| 5 | gynnwys y canlynol |
142,458 |
4-grams (Word):
| Rank | N-gram | Count |
|---|---|---|
| 1 | unol daleithiau america saesneg |
183,879 |
| 2 | gan gynnwys y canlynol |
142,457 |
| 3 | o ffilmiau gan gynnwys |
141,034 |
| 4 | nifer o ffilmiau gan |
141,018 |
| 5 | ffilmiau gan gynnwys y |
141,004 |
5-grams (Word):
| Rank | N-gram | Count |
|---|---|---|
| 1 | nifer o ffilmiau gan gynnwys |
141,016 |
| 2 | o ffilmiau gan gynnwys y |
141,003 |
| 3 | ffilmiau gan gynnwys y canlynol |
140,997 |
| 4 | y nodwyd cyhoeddwyd y ffilm |
140,932 |
| 5 | fel y nodwyd cyhoeddwyd y |
140,932 |
2-grams (Subword):
| Rank | N-gram | Count |
|---|---|---|
| 1 | n _ |
6,965,988 |
| 2 | d _ |
6,143,531 |
| 3 | _ y |
5,977,485 |
| 4 | d d |
5,740,307 |
| 5 | _ a |
5,232,448 |
3-grams (Subword):
| Rank | N-gram | Count |
|---|---|---|
| 1 | y n _ |
2,646,508 |
| 2 | d d _ |
2,490,077 |
| 3 | _ y n |
2,304,841 |
| 4 | w y d |
2,285,145 |
| 5 | _ y _ |
2,240,041 |
4-grams (Subword):
| Rank | N-gram | Count |
|---|---|---|
| 1 | _ y n _ |
2,171,280 |
| 2 | f i l m |
1,586,546 |
| 3 | f f i l |
1,571,751 |
| 4 | _ f f i |
1,455,954 |
| 5 | i l m _ |
1,222,896 |
5-grams (Subword):
| Rank | N-gram | Count |
|---|---|---|
| 1 | f f i l m |
1,569,304 |
| 2 | _ f f i l |
1,419,063 |
| 3 | f i l m _ |
1,222,863 |
| 4 | _ g a n _ |
924,207 |
| 5 | w y d _ y |
781,315 |
Key Findings
- Best Perplexity: 2-gram (subword) with 266
- Entropy Trend: Decreases with larger n-grams (more predictable)
- Coverage: Top-1000 patterns cover ~38% 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 | 0.9977 | 1.997 | 9.84 | 671,269 | 0.2% |
| 1 | Subword | 1.0862 | 2.123 | 6.65 | 8,673 | 0.0% |
| 2 | Word | 0.3690 | 1.291 | 2.18 | 6,591,949 | 63.1% |
| 2 | Subword | 0.6157 | 1.532 | 3.90 | 57,679 | 38.4% |
| 3 | Word | 0.1502 | 1.110 | 1.34 | 14,351,859 | 85.0% |
| 3 | Subword | 0.6340 | 1.552 | 3.78 | 225,011 | 36.6% |
| 4 | Word | 0.0687 🏆 | 1.049 | 1.14 | 19,154,889 | 93.1% |
| 4 | Subword | 0.6561 | 1.576 | 3.40 | 850,309 | 34.4% |
Generated Text Samples (Word-based)
Below are text samples generated from each word-based Markov chain model:
Context Size 1:
y ffindir gweler hefyd cyhoeddodd nifer o r almaen almaenegno unknown value the white ship mutinyyn ystod eang derbyniad gweler hefyd rhestr goch yr enw tacson delwedd gwlad dyddiad a 22o leiaf 1 050 o ffilmiau gan nifer o fariau cul o awstria almaeneg cyfeiriadau gan
Context Size 2:
unol daleithiau america rhamantaidd gyda llai na 10 o actorion lleisiol a olygwyd gan mogens skot ha...daleithiau america cyfeiriadau gan gyfarwyddwyr ffilm gwrywaidd saesneg du a gwyn o japan mud sydd a...y ffilm hon yw warner baxter stuart erwin edmund lowe cafodd ei ddanfon gan fyddin a adwaenid
Context Size 3:
unol daleithiau america in every womans life unol daleithiau america saesneg the boys from brazil a ...daleithiau america saesneg cyfeiriadau gan gyfarwyddwyr ffilm gwrywaidd tsieceg o tsiecoslofacia gyd...gan y cyfarwyddwr kevin billington yw the rise of the nazis stalingrad fernsehepisode y deyrnas uned...
Context Size 4:
unol daleithiau america saesneg o unol daleithiau america arswyd o unol daleithiau america comedi gy...gan gynnwys y canlynol cyfeiriadau lliw lliw o sbaen rhamantaidd o sbaen sbaeneg o sbaen comedi gyda...o ffilmiau gan gynnwys y canlynol ffilm delwedd gwlad iaith wreiddiol dyddiad coyote summer unol dal...
Generated Text Samples (Subword-based)
Below are text samples generated from each subword-based Markov chain model:
Context Size 1:
_o/uchomau_dcolmadankeegoeei'choelm_seratir,_pae
Context Size 2:
n_gannwyddyd_gwedd_rasalanc_wr_pon_y_faraithia_cymg
Context Size 3:
yn_wreidd_gwyn_cyhdd_a_10,700_strwyd_yn_coln,_sy'n_alm
Context Size 4:
_yn_sydd_('cyfarwydfilmio_oeddwyd,_cyhffilm_hon_walter,_j
Key Findings
- Best Predictability: Context-4 (word) with 93.1% predictability
- Branching Factor: Decreases with context size (more deterministic)
- Memory Trade-off: Larger contexts require more storage (850,309 contexts)
- Recommendation: Context-3 or Context-4 for text generation
4. Vocabulary Analysis
Statistics
| Metric | Value |
|---|---|
| Vocabulary Size | 360,120 |
| Total Tokens | 54,213,529 |
| Mean Frequency | 150.54 |
| Median Frequency | 5 |
| Frequency Std Dev | 7791.16 |
Most Common Words
| Rank | Word | Frequency |
|---|---|---|
| 1 | y | 2,261,654 |
| 2 | yn | 2,177,991 |
| 3 | o | 1,594,538 |
| 4 | a | 1,391,156 |
| 5 | ffilm | 1,218,819 |
| 6 | gan | 925,486 |
| 7 | r | 723,127 |
| 8 | i | 650,709 |
| 9 | yr | 521,021 |
| 10 | daleithiau | 501,348 |
Least Common Words (from vocabulary)
| Rank | Word | Frequency |
|---|---|---|
| 1 | geirfaoedd | 2 |
| 2 | volcabulaire | 2 |
| 3 | ethnolog | 2 |
| 4 | siculu | 2 |
| 5 | metafonetig | 2 |
| 6 | prano | 2 |
| 7 | defynydd | 2 |
| 8 | clwsterau | 2 |
| 9 | ŋm | 2 |
| 10 | ŋw | 2 |
Zipf's Law Analysis
| Metric | Value |
|---|---|
| Zipf Coefficient | 1.1638 |
| R² (Goodness of Fit) | 0.998189 |
| Adherence Quality | excellent |
Coverage Analysis
| Top N Words | Coverage |
|---|---|
| Top 100 | 49.6% |
| Top 1,000 | 72.6% |
| Top 5,000 | 84.6% |
| Top 10,000 | 88.7% |
Key Findings
- Zipf Compliance: R²=0.9982 indicates excellent adherence to Zipf's law
- High Frequency Dominance: Top 100 words cover 49.6% of corpus
- Long Tail: 350,120 words needed for remaining 11.3% 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 | 0.8420 🏆 | 0.3264 | N/A | N/A |
| mono_64d | 64 | 0.8198 | 0.2681 | N/A | N/A |
| mono_128d | 128 | 0.7807 | 0.2230 | N/A | N/A |
| aligned_32d | 32 | 0.8420 | 0.3314 | 0.2180 | 0.6520 |
| aligned_64d | 64 | 0.8198 | 0.2651 | 0.3480 | 0.7540 |
| aligned_128d | 128 | 0.7807 | 0.2238 | 0.5000 | 0.8640 |
Key Findings
- Best Isotropy: mono_32d with 0.8420 (more uniform distribution)
- Semantic Density: Average pairwise similarity of 0.2730. Lower values indicate better semantic separation.
- Alignment Quality: Aligned models achieve up to 50.0% 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 | -0.043 | 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 |
|---|
Productive Suffixes
| Suffix | Examples |
|---|---|
-er |
menschenfresser, spengler, giessler |
-dd |
cwmnioedd, ailysgrifennodd, maswedd |
-on |
cenawon, pittston, dimson |
-au |
llinachau, rygiau, halennau |
-en |
vorsitzenden, misshandlingen, ddiacen |
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 |
|---|---|---|---|
iada |
2.24x | 67 contexts | riada, viada, diada |
efyd |
2.21x | 69 contexts | hefyd, lefyd, efydd |
ddio |
1.98x | 84 contexts | addio, ddiog, ddios |
feir |
2.03x | 69 contexts | feiro, feira, sfeir |
nnwy |
2.19x | 46 contexts | annwyl, annwyd, gynnwy |
leit |
2.36x | 32 contexts | leite, fleit, leith |
yddi |
1.71x | 121 contexts | fyddi, byddi, dyddio |
dwyd |
2.14x | 43 contexts | nodwyd, ildwyd, codwyd |
ithi |
1.55x | 152 contexts | deithi, teithi, rithio |
alei |
2.30x | 26 contexts | dalei, malei, maleia |
adau |
2.02x | 40 contexts | badau, gadau, fadau |
eddw |
1.67x | 49 contexts | feddw, weddw, meddw |
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 |
|---|---|---|---|
| deiamwntau | deiamwnt-au |
4.5 | deiamwnt |
| croniclau | cronicl-au |
4.5 | cronicl |
| komödianten | komödiant-en |
4.5 | komödiant |
| recruiter | recruit-er |
4.5 | recruit |
| diffiniodd | diffinio-dd |
4.5 | diffinio |
| catholicon | catholic-on |
4.5 | catholic |
| telesgopau | telesgop-au |
4.5 | telesgop |
| canlyniadau | canlyniad-au |
4.5 | canlyniad |
| lluswydden | lluswy-dd-en |
3.0 | lluswy |
| organeddau | organe-dd-au |
3.0 | organe |
| chynffonau | chynff-on-au |
3.0 | chynff |
| wastadeddau | wastade-dd-au |
3.0 | wastade |
| ffilmymgyrchydd | ffilmymgyrchy-dd |
1.5 | ffilmymgyrchy |
| stabilizer | stabiliz-er |
1.5 | stabiliz |
| effeithiolrwydd | effeithiolrwy-dd |
1.5 | effeithiolrwy |
6.6 Linguistic Interpretation
Automated Insight: The language Welsh 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 (4.11x) |
| N-gram | 2-gram | Lowest perplexity (266) |
| Markov | Context-4 | Highest predictability (93.1%) |
| 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) × 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: 2026-01-04 02:01:49



















