language: ltg
language_name: Latgalian
language_family: baltic
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-baltic
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: 5.184
- name: best_isotropy
type: isotropy
value: 0.4321
- name: vocabulary_size
type: vocab
value: 0
generated: 2026-01-10T00:00:00.000Z
Latgalian - Wikilangs Models
Comprehensive Research Report & Full Ablation Study
This repository contains NLP models trained and evaluated by Wikilangs, specifically on Latgalian 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 | 3.845x | 3.85 | 0.1136% | 209,537 |
| 16k | 4.349x | 4.35 | 0.1284% | 185,293 |
| 32k | 4.833x | 4.84 | 0.1428% | 166,704 |
| 64k | 5.184x 🏆 | 5.19 | 0.1531% | 155,441 |
Tokenization Examples
Below are sample sentences tokenized with each vocabulary size:
Sample 1: Hernmans von Baļke () beja pyrmais Livonejis ordyna magistris. Beja daguojumūs n...
| Vocab | Tokens | Count |
|---|---|---|
| 8k | ▁h ern mans ▁von ▁baļ ke ▁() ▁beja ▁pyrmais ▁livonejis ... (+19 more) |
29 |
| 16k | ▁hern mans ▁von ▁baļ ke ▁() ▁beja ▁pyrmais ▁livonejis ▁ordyna ... (+17 more) |
27 |
| 32k | ▁hern mans ▁von ▁baļke ▁() ▁beja ▁pyrmais ▁livonejis ▁ordyna ▁magistris ... (+15 more) |
25 |
| 64k | ▁hernmans ▁von ▁baļke ▁() ▁beja ▁pyrmais ▁livonejis ▁ordyna ▁magistris . ... (+14 more) |
24 |
Sample 2: Tbilisi — Gruzejis golvysmīsts i pats leluokais mīsts.
| Vocab | Tokens | Count |
|---|---|---|
| 8k | ▁t b ilis i ▁— ▁gr uz ejis ▁golvysmīsts ▁i ... (+4 more) |
14 |
| 16k | ▁t b ilis i ▁— ▁gruz ejis ▁golvysmīsts ▁i ▁pats ... (+3 more) |
13 |
| 32k | ▁tbilisi ▁— ▁gruzejis ▁golvysmīsts ▁i ▁pats ▁leluokais ▁mīsts . |
9 |
| 64k | ▁tbilisi ▁— ▁gruzejis ▁golvysmīsts ▁i ▁pats ▁leluokais ▁mīsts . |
9 |
Sample 3: Bygucs irā latgaļu tradicionalais gavieņa laika iedīņs nu sadukurātu buļbu, pupu...
| Vocab | Tokens | Count |
|---|---|---|
| 8k | ▁by gu cs ▁irā ▁latgaļu ▁tradicionalais ▁gavieņa ▁laika ▁iedīņs ▁nu ... (+13 more) |
23 |
| 16k | ▁bygucs ▁irā ▁latgaļu ▁tradicionalais ▁gavieņa ▁laika ▁iedīņs ▁nu ▁sad ukur ... (+9 more) |
19 |
| 32k | ▁bygucs ▁irā ▁latgaļu ▁tradicionalais ▁gavieņa ▁laika ▁iedīņs ▁nu ▁sadukur ātu ... (+8 more) |
18 |
| 64k | ▁bygucs ▁irā ▁latgaļu ▁tradicionalais ▁gavieņa ▁laika ▁iedīņs ▁nu ▁sadukurātu ▁buļbu ... (+7 more) |
17 |
Key Findings
- Best Compression: 64k achieves 5.184x compression
- Lowest UNK Rate: 8k with 0.1136% 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 | 1,129 | 10.14 | 1,614 | 26.6% | 83.1% |
| 2-gram | Subword | 359 🏆 | 8.49 | 1,848 | 58.3% | 98.7% |
| 3-gram | Word | 1,202 | 10.23 | 1,863 | 29.0% | 79.0% |
| 3-gram | Subword | 2,922 | 11.51 | 12,393 | 21.1% | 65.0% |
| 4-gram | Word | 2,659 | 11.38 | 4,039 | 21.2% | 54.7% |
| 4-gram | Subword | 12,757 | 13.64 | 46,485 | 11.1% | 36.0% |
| 5-gram | Word | 2,091 | 11.03 | 3,145 | 23.8% | 59.7% |
| 5-gram | Subword | 28,000 | 14.77 | 80,144 | 8.2% | 25.4% |
Top 5 N-grams by Size
2-grams (Word):
| Rank | N-gram | Count |
|---|---|---|
| 1 | nūruodis i |
196 |
| 2 | i olūti |
196 |
| 3 | nūvoda teritoriskais |
159 |
| 4 | teritoriskais padalīņs |
157 |
| 5 | pogosts irā |
136 |
3-grams (Word):
| Rank | N-gram | Count |
|---|---|---|
| 1 | nūruodis i olūti |
196 |
| 2 | nūvoda teritoriskais padalīņs |
135 |
| 3 | teritoriskais padalīņs vydzemē |
83 |
| 4 | padalīņs vydzemē pogosta |
73 |
| 5 | vydzemē pogosta centrys |
71 |
4-grams (Word):
| Rank | N-gram | Count |
|---|---|---|
| 1 | nūvoda teritoriskais padalīņs vydzemē |
77 |
| 2 | teritoriskais padalīņs vydzemē pogosta |
73 |
| 3 | padalīņs vydzemē pogosta centrys |
71 |
| 4 | pogosts tur rūbežu ar |
50 |
| 5 | a s preses nams |
44 |
5-grams (Word):
| Rank | N-gram | Count |
|---|---|---|
| 1 | nūvoda teritoriskais padalīņs vydzemē pogosta |
73 |
| 2 | teritoriskais padalīņs vydzemē pogosta centrys |
71 |
| 3 | pagasti enciklopēdija a s preses |
42 |
| 4 | latvijas pagasti enciklopēdija a s |
42 |
| 5 | a s preses nams rīga |
42 |
2-grams (Subword):
| Rank | N-gram | Count |
|---|---|---|
| 1 | s _ |
26,697 |
| 2 | a _ |
14,824 |
| 3 | _ p |
11,899 |
| 4 | u _ |
11,109 |
| 5 | u o |
10,394 |
3-grams (Subword):
| Rank | N-gram | Count |
|---|---|---|
| 1 | y s _ |
7,166 |
| 2 | i s _ |
5,868 |
| 3 | _ i _ |
3,658 |
| 4 | s _ p |
3,356 |
| 5 | _ p a |
3,202 |
4-grams (Subword):
| Rank | N-gram | Count |
|---|---|---|
| 1 | _ p o g |
2,252 |
| 2 | g o s t |
2,247 |
| 3 | p o g o |
2,246 |
| 4 | o g o s |
2,243 |
| 5 | j i s _ |
2,080 |
5-grams (Subword):
| Rank | N-gram | Count |
|---|---|---|
| 1 | p o g o s |
2,242 |
| 2 | o g o s t |
2,242 |
| 3 | _ p o g o |
2,222 |
| 4 | e j i s _ |
1,847 |
| 5 | _ l a t g |
1,295 |
Key Findings
- Best Perplexity: 2-gram (subword) with 359
- 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 | 0.5622 | 1.477 | 2.79 | 29,368 | 43.8% |
| 1 | Subword | 1.2575 | 2.391 | 10.03 | 386 | 0.0% |
| 2 | Word | 0.1160 | 1.084 | 1.18 | 81,444 | 88.4% |
| 2 | Subword | 1.1593 | 2.234 | 6.15 | 3,869 | 0.0% |
| 3 | Word | 0.0312 | 1.022 | 1.04 | 95,629 | 96.9% |
| 3 | Subword | 0.8465 | 1.798 | 3.54 | 23,778 | 15.3% |
| 4 | Word | 0.0149 🏆 | 1.010 | 1.02 | 99,029 | 98.5% |
| 4 | Subword | 0.5542 | 1.468 | 2.20 | 84,057 | 44.6% |
Generated Text Samples (Word-based)
Below are text samples generated from each word-based Markov chain model:
Context Size 1:
i aļternativuos muzykys školā nu nazcik myudu iz zemi nūpierka lītovys i sagvuordus sovetu matematik...nu 14 3 limbažu nūvoda teritoriskais padalīņs vydzemē kas tam normali izapiļdeit i snīgs izkreit dek...irā latgaļu izdavumu izguoja pošā laikā pa cytam elementam atributu style stiļs 18 godu tyukstūšys r...
Context Size 2:
nūruodis i olūti viesture sadraudzeiba nūruodis i olūti janina kūrseite anna stafecka latgola volūda...nūvoda teritoriskais padalīņs vydzemē i latgolā kai golvonuo europys areala dīnavydu rūbežā napalelā...teritoriskais padalīņs vydzemē pogosta centrys skuki pleiki nauļāni gromyki auguļova jonini zeimeigi...
Context Size 3:
nūvoda teritoriskais padalīņs vydzemē kas sasadora 3 pogostim brenguļu kauguru i trykuotys pogostanūruodis i olūti teiklavītys raudive anas platyrhynchos raudiveteritoriskais padalīņs vydzemē pogosta centrys galgovska nūruodis teiklavītys galgovskys pogosts guļ...
Context Size 4:
nūvoda teritoriskais padalīņs vydzemē pogosta centrys burtinīks nūruodis teiklavītys burtinīka pogos...teritoriskais padalīņs vydzemē pogosta centrys vylpulka nūruodispadalīņs vydzemē pogosta centrys jaunlaicine nūruodis
Generated Text Samples (Subword-based)
Below are text samples generated from each subword-based Markov chain model:
Context Size 1:
_pe_kra,_da_pā._aitui_nacylūdicās_iaieists_bogot
Context Size 2:
s_pojs._dasdīņs_ca_i_linacānu_īlī__pošonoja_iseito_
Context Size 3:
ys_planamsa_punktiis_austrumā._nūvod_i_medņovysova_dor
Context Size 4:
_pogostā_dzeiguo_pagostā,_gods_canadā_pogostu_pogosts_var
Key Findings
- Best Predictability: Context-4 (word) with 98.5% predictability
- Branching Factor: Decreases with context size (more deterministic)
- Memory Trade-off: Larger contexts require more storage (84,057 contexts)
- Recommendation: Context-3 or Context-4 for text generation
4. Vocabulary Analysis
Statistics
| Metric | Value |
|---|---|
| Vocabulary Size | 10,308 |
| Total Tokens | 93,904 |
| Mean Frequency | 9.11 |
| Median Frequency | 3 |
| Frequency Std Dev | 48.87 |
Most Common Words
| Rank | Word | Frequency |
|---|---|---|
| 1 | i | 3,760 |
| 2 | nu | 1,224 |
| 3 | pogosts | 1,012 |
| 4 | irā | 958 |
| 5 | ar | 789 |
| 6 | godā | 708 |
| 7 | nūvoda | 575 |
| 8 | a | 505 |
| 9 | pogosta | 483 |
| 10 | kai | 466 |
Least Common Words (from vocabulary)
| Rank | Word | Frequency |
|---|---|---|
| 1 | said | 2 |
| 2 | little | 2 |
| 3 | baby | 2 |
| 4 | hide | 2 |
| 5 | much | 2 |
| 6 | see | 2 |
| 7 | izjemūt | 2 |
| 8 | way | 2 |
| 9 | garden | 2 |
| 10 | drupys | 2 |
Zipf's Law Analysis
| Metric | Value |
|---|---|
| Zipf Coefficient | 0.9146 |
| R² (Goodness of Fit) | 0.986958 |
| Adherence Quality | excellent |
Coverage Analysis
| Top N Words | Coverage |
|---|---|
| Top 100 | 30.0% |
| Top 1,000 | 62.1% |
| Top 5,000 | 87.4% |
| Top 10,000 | 99.3% |
Key Findings
- Zipf Compliance: R²=0.9870 indicates excellent adherence to Zipf's law
- High Frequency Dominance: Top 100 words cover 30.0% of corpus
- Long Tail: 308 words needed for remaining 0.7% 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 | 0.4321 🏆 | 0.4107 | N/A | N/A |
| mono_64d | 64 | 0.1003 | 0.4086 | N/A | N/A |
| mono_128d | 128 | 0.0125 | 0.4060 | N/A | N/A |
| aligned_32d | 32 | 0.4321 | 0.4131 | 0.0160 | 0.1700 |
| aligned_64d | 64 | 0.1003 | 0.3974 | 0.0420 | 0.2080 |
| aligned_128d | 128 | 0.0125 | 0.3946 | 0.0780 | 0.2380 |
Key Findings
- Best Isotropy: mono_32d with 0.4321 (more uniform distribution)
- Semantic Density: Average pairwise similarity of 0.4051. Lower values indicate better semantic separation.
- Alignment Quality: Aligned models achieve up to 7.8% 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 | 1.350 | 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 |
|---|---|
-s |
senegals, sataisūt, svātuo |
-p |
pasauktys, point, pamat |
-k |
kryšānu, koru, kleštoru |
-a |
atlaidys, american, aleksandris |
-m |
magma, muzykā, musulmoni |
-v |
vītolvys, vosor, vacupē |
-d |
dolaru, dekters, desmarest |
-l |
lels, lūkūt, likvidātuo |
Productive Suffixes
| Suffix | Examples |
|---|---|
-s |
atlaidys, lels, uralensis |
-a |
opera, magma, garuma |
-u |
kryšānu, dolaru, koru |
-ys |
atlaidys, pasauktys, sardzeibys |
-is |
uralensis, rusifikacejis, aleksandris |
-i |
cierkvi, rogi, sīvīti |
-ja |
antologija, sarja, pasaruodeja |
-ā |
taidā, muzykā, okā |
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 |
|---|---|---|---|
ejis |
1.65x | 30 contexts | mejis, bejis, siejis |
stei |
1.50x | 30 contexts | vaļstei, raksteit, raksteis |
olūd |
2.03x | 9 contexts | volūdu, volūda, volūdā |
skai |
1.45x | 23 contexts | skaitu, skaitā, skaits |
zeiv |
1.65x | 14 contexts | dzeiv, dzeivo, dzeive |
volū |
2.03x | 8 contexts | volūdu, volūda, volūdā |
atga |
2.00x | 8 contexts | latgali, latgale, latgaļu |
dzei |
1.44x | 19 contexts | dzeiv, dzeivo, dzeive |
eiby |
1.76x | 10 contexts | vīneibys, vareibys, ticeibys |
teib |
1.59x | 13 contexts | tauteibu, plateibu, kusteiba |
ūvod |
1.90x | 8 contexts | nūvoda, nūvodā, nūvodu |
nūvo |
1.90x | 8 contexts | nūvoda, nūvodā, nūvodu |
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 |
|---|---|---|---|
-p |
-s |
264 words | pošleluos, pyrmškolys |
-s |
-s |
246 words | sacapums, saroksts |
-a |
-s |
196 words | astis, auss |
-v |
-s |
178 words | vydtautyskūs, vydslaikūs |
-d |
-s |
146 words | doktoranturys, dīnavydlatgolys |
-k |
-s |
146 words | katuoleibys, kusteibys |
-p |
-a |
145 words | pebraļa, pabeigta |
-m |
-s |
118 words | maratons, mežūtnis |
-l |
-s |
113 words | laikvuords, lingvists |
-s |
-a |
111 words | sloveneja, statusa |
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 |
|---|---|---|---|
| izacēluse | izacēlu-s-e |
7.5 | s |
| bengalensis | bengalen-s-is |
7.5 | s |
| publiciejuse | publicieju-s-e |
7.5 | s |
| buoreņtīsa | buoreņtī-s-a |
7.5 | s |
| afrikaans | afrika-a-ns |
7.5 | a |
| literārajā | literār-a-jā |
7.5 | a |
| frameless | framele-s-s |
7.5 | s |
| izacāluse | izacālu-s-e |
7.5 | s |
| hondurass | hondura-s-s |
7.5 | s |
| phillipsi | phillip-s-i |
7.5 | s |
| izslyvušajā | izslyvuš-a-jā |
7.5 | a |
| golvonais | golvon-a-is |
7.5 | a |
| desmarest | desmare-s-t |
7.5 | s |
| atsaroduse | atsarodu-s-e |
7.5 | s |
| rūkroksti | rūkrok-s-ti |
7.5 | s |
6.6 Linguistic Interpretation
Automated Insight: The language Latgalian 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 (5.18x) |
| N-gram | 2-gram | Lowest perplexity (359) |
| Markov | Context-4 | Highest predictability (98.5%) |
| 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: 2026-01-10 11:25:06



















