Slovak - Wikilangs Models
Comprehensive Research Report & Full Ablation Study
This repository contains NLP models trained and evaluated by Wikilangs, specifically on Slovak 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 | 3.384x | 3.39 | 0.1078% | 1,294,485 |
| 16k | 3.810x | 3.81 | 0.1214% | 1,149,866 |
| 32k | 4.234x | 4.24 | 0.1349% | 1,034,640 |
| 64k | 4.618x π | 4.62 | 0.1472% | 948,528 |
Tokenization Examples
Below are sample sentences tokenized with each vocabulary size:
Sample 1: TeatrΓ‘lnosΕ₯ je strojenΓ© sprΓ‘vanie, vystupovanie; strojenosΕ₯; okΓ‘zalosΕ₯. ExternΓ© ...
| Vocab | Tokens | Count |
|---|---|---|
| 8k | βte at rΓ‘l nosΕ₯ βje βstroj enΓ© βsprΓ‘ vanie , ... (+14 more) |
24 |
| 16k | βte at rΓ‘l nosΕ₯ βje βstroj enΓ© βsprΓ‘vanie , βvystup ... (+12 more) |
22 |
| 32k | βte at rΓ‘l nosΕ₯ βje βstroj enΓ© βsprΓ‘vanie , βvystup ... (+11 more) |
21 |
| 64k | βte at rΓ‘l nosΕ₯ βje βstroj enΓ© βsprΓ‘vanie , βvystupovanie ... (+10 more) |
20 |
Sample 2: 205 Martha je planΓ©tka v hlavnom pΓ‘se planΓ©tok. InΓ© projekty ExternΓ© odkazy 1 β ...
| Vocab | Tokens | Count |
|---|---|---|
| 8k | β 2 0 5 βmar tha βje βplanΓ©tka βv βhlavnom ... (+20 more) |
30 |
| 16k | β 2 0 5 βmar tha βje βplanΓ©tka βv βhlavnom ... (+19 more) |
29 |
| 32k | β 2 0 5 βmar tha βje βplanΓ©tka βv βhlavnom ... (+18 more) |
28 |
| 64k | β 2 0 5 βmartha βje βplanΓ©tka βv βhlavnom βpΓ‘se ... (+17 more) |
27 |
Sample 3: Mopsus mΓ΄ΕΎe byΕ₯: latinskΓ½ nΓ‘zov grΓ©ckej mytologickej postavy, pozri Mopsos rod p...
| Vocab | Tokens | Count |
|---|---|---|
| 8k | βmo ps us βmΓ΄ΕΎe βbyΕ₯ : βlatin skΓ½ βnΓ‘zov βgrΓ©ckej ... (+22 more) |
32 |
| 16k | βmo ps us βmΓ΄ΕΎe βbyΕ₯ : βlatin skΓ½ βnΓ‘zov βgrΓ©ckej ... (+19 more) |
29 |
| 32k | βmo ps us βmΓ΄ΕΎe βbyΕ₯ : βlatinskΓ½ βnΓ‘zov βgrΓ©ckej βmyto ... (+18 more) |
28 |
| 64k | βmo ps us βmΓ΄ΕΎe βbyΕ₯ : βlatinskΓ½ βnΓ‘zov βgrΓ©ckej βmyto ... (+17 more) |
27 |
Key Findings
- Best Compression: 64k achieves 4.618x compression
- Lowest UNK Rate: 8k with 0.1078% 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 | 194,679 | 17.57 | 1,294,124 | 9.6% | 19.4% |
| 2-gram | Subword | 436 π | 8.77 | 14,570 | 55.9% | 97.9% |
| 3-gram | Word | 313,082 | 18.26 | 1,894,773 | 11.8% | 18.9% |
| 3-gram | Subword | 4,546 | 12.15 | 139,891 | 17.1% | 55.9% |
| 4-gram | Word | 450,373 | 18.78 | 2,990,666 | 13.9% | 19.7% |
| 4-gram | Subword | 29,988 | 14.87 | 892,283 | 7.0% | 26.0% |
| 5-gram | Word | 245,160 | 17.90 | 2,133,494 | 17.8% | 24.5% |
| 5-gram | Subword | 135,044 | 17.04 | 3,317,079 | 3.9% | 15.4% |
Top 5 N-grams by Size
2-grams (Word):
| Rank | N-gram | Count |
|---|---|---|
| 1 | v roku |
239,095 |
| 2 | externΓ© odkazy |
86,205 |
| 3 | v departemente |
81,770 |
| 4 | pozri aj |
80,426 |
| 5 | inΓ© projekty |
61,467 |
3-grams (Word):
| Rank | N-gram | Count |
|---|---|---|
| 1 | pozri aj zoznam |
55,568 |
| 2 | referencie pozri aj |
53,094 |
| 3 | aj zoznam obcΓ |
41,598 |
| 4 | sa nachΓ‘dza v |
41,376 |
| 5 | ktorΓ‘ sa nachΓ‘dza |
37,349 |
4-grams (Word):
| Rank | N-gram | Count |
|---|---|---|
| 1 | referencie pozri aj zoznam |
44,925 |
| 2 | pozri aj zoznam obcΓ |
41,597 |
| 3 | ktorΓ‘ sa nachΓ‘dza v |
36,794 |
| 4 | dostupnΓ© online po francΓΊzsky |
36,767 |
| 5 | insee dostupnΓ© online po |
36,760 |
5-grams (Word):
| Rank | N-gram | Count |
|---|---|---|
| 1 | referencie pozri aj zoznam obcΓ |
41,480 |
| 2 | insee dostupnΓ© online po francΓΊzsky |
36,760 |
| 3 | mΓ‘ rozlohu najvyΕ‘Ε‘Γ bod je |
36,532 |
| 4 | institut national de la statistique |
36,530 |
| 5 | national de la statistique et |
36,529 |
2-grams (Subword):
| Rank | N-gram | Count |
|---|---|---|
| 1 | a _ |
8,087,656 |
| 2 | _ p |
5,509,644 |
| 3 | _ s |
5,383,985 |
| 4 | e _ |
5,252,691 |
| 5 | _ v |
4,866,750 |
3-grams (Subword):
| Rank | N-gram | Count |
|---|---|---|
| 1 | _ p r |
2,185,530 |
| 2 | _ p o |
2,090,423 |
| 3 | _ v _ |
1,919,460 |
| 4 | _ n a |
1,809,529 |
| 5 | _ a _ |
1,552,905 |
4-grams (Subword):
| Rank | N-gram | Count |
|---|---|---|
| 1 | _ n a _ |
904,134 |
| 2 | _ s a _ |
814,412 |
| 3 | _ p r e |
785,964 |
| 4 | _ j e _ |
682,133 |
| 5 | Γ½ c h _ |
668,796 |
5-grams (Subword):
| Rank | N-gram | Count |
|---|---|---|
| 1 | _ k t o r |
496,744 |
| 2 | , _ k t o |
404,467 |
| 3 | _ r o k u |
369,877 |
| 4 | r o k u _ |
354,960 |
| 5 | _ v _ r o |
291,692 |
Key Findings
- Best Perplexity: 2-gram (subword) with 436
- Entropy Trend: Decreases with larger n-grams (more predictable)
- Coverage: Top-1000 patterns cover ~15% 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 | 1.0430 | 2.060 | 11.55 | 1,699,952 | 0.0% |
| 1 | Subword | 1.0314 | 2.044 | 7.25 | 6,754 | 0.0% |
| 2 | Word | 0.3261 | 1.254 | 1.98 | 19,608,492 | 67.4% |
| 2 | Subword | 0.7796 | 1.717 | 5.79 | 48,928 | 22.0% |
| 3 | Word | 0.1115 | 1.080 | 1.22 | 38,651,293 | 88.9% |
| 3 | Subword | 0.8417 | 1.792 | 5.12 | 283,324 | 15.8% |
| 4 | Word | 0.0420 π | 1.030 | 1.07 | 46,960,073 | 95.8% |
| 4 | Subword | 0.7681 | 1.703 | 3.95 | 1,449,998 | 23.2% |
Generated Text Samples (Word-based)
Below are text samples generated from each word-based Markov chain model:
Context Size 1:
v lese i video z medzinΓ‘rodnej ΓΊnie Δlenovia pΓ‘tracΓch technikΓ‘ch v rΓ‘mci ukrajinskej po jej kritiko...a jej hmoty ktorΓ‘ pΓ΄sobila ako spotrebiteΔΎ spoliehal na predaj viac skomplikovala proti aerodactylov...na rozjazd prostrednΓctvom svojich smarfΓ³nov tΓΊto procedΓΊru nΓzkoΓΊrovΕovΓ©ho formΓ‘tovania prΓspevkov ...
Context Size 2:
v roku Ε‘tatistickΓ½ ΓΊrad slovenskej republiky bratislava ΓΊrad geodΓ©zie a kartografie Δ z z balΓ‘ΕΎ 3 00externΓ© odkazy fridrich viliam bol vnukom krΓ©thea zakladateΔΎa iΓ³lku v tesΓ‘lii boli bojovnΓkmi v tora...v departemente vienne v departemente seine maritime mestom pretekΓ‘ rieka plouΔnice ktorΓ‘ sa nachΓ‘dza...
Context Size 3:
pozri aj zoznam obcΓ departementu eure et loir v departemente eure v regiΓ³ne hornΓ‘ normandia poloha ...referencie pozri aj zoznam obcΓ v Δesku inΓ© projekty externΓ© odkazy arthur penn na fdb cz fedor bart...aj zoznam obcΓ departementu haute marne v regiΓ³ne champagne ardenne poloha obec mΓ‘ rozlohu najvyΕ‘Ε‘Γ ...
Context Size 4:
referencie pozri aj zoznam obcΓ departementu manche v departemente manche svetovΓ©ho dediΔstva vo fra...pozri aj zoznam obcΓ departementu corse du sud v regiΓ³ne korzika poloha obec mΓ‘ rozlohu najvyΕ‘Ε‘Γ bod...ktorΓ‘ sa nachΓ‘dza v departemente landes v regiΓ³ne akvitΓ‘nsko poloha obec mΓ‘ rozlohu najvyΕ‘Ε‘Γ bod je ...
Generated Text Samples (Subword-based)
Below are text samples generated from each subword-based Markov chain model:
Context Size 1:
_pu_ora_pova_ov-ou_famuhl_vy_svna_prekupokoduln_
Context Size 2:
a_prvΓ©_do_isymba__prΓ_otnΓΊ,_ktorΓ©c_sanskΓ½_v_proje,_
Context Size 3:
_predoventaina...__po_udrΕΎby_kom_pod_v_za_na_na_sa_vym
Context Size 4:
_na_tzv._etapokojnΓ½_sa_celkovej_afroam_pre_rΓ΄zneho_hudby_
Key Findings
- Best Predictability: Context-4 (word) with 95.8% predictability
- Branching Factor: Decreases with context size (more deterministic)
- Memory Trade-off: Larger contexts require more storage (1,449,998 contexts)
- Recommendation: Context-3 or Context-4 for text generation
4. Vocabulary Analysis
Statistics
| Metric | Value |
|---|---|
| Vocabulary Size | 820,443 |
| Total Tokens | 58,682,268 |
| Mean Frequency | 71.53 |
| Median Frequency | 4 |
| Frequency Std Dev | 3539.87 |
Most Common Words
| Rank | Word | Frequency |
|---|---|---|
| 1 | v | 1,958,659 |
| 2 | a | 1,592,669 |
| 3 | na | 911,291 |
| 4 | sa | 823,676 |
| 5 | je | 689,206 |
| 6 | z | 435,689 |
| 7 | s | 419,380 |
| 8 | roku | 369,840 |
| 9 | do | 304,080 |
| 10 | aj | 295,406 |
Least Common Words (from vocabulary)
| Rank | Word | Frequency |
|---|---|---|
| 1 | reorganizaΔnΓΊ | 2 |
| 2 | kamb | 2 |
| 3 | patenting | 2 |
| 4 | Δasobitie | 2 |
| 5 | cΓ‘pizu | 2 |
| 6 | capizu | 2 |
| 7 | bookstagramovej | 2 |
| 8 | bookstagrame | 2 |
| 9 | nevzlietne | 2 |
| 10 | marusov | 2 |
Zipf's Law Analysis
| Metric | Value |
|---|---|
| Zipf Coefficient | 0.9228 |
| RΒ² (Goodness of Fit) | 0.998599 |
| Adherence Quality | excellent |
Coverage Analysis
| Top N Words | Coverage |
|---|---|
| Top 100 | 27.5% |
| Top 1,000 | 47.2% |
| Top 5,000 | 63.8% |
| Top 10,000 | 71.4% |
Key Findings
- Zipf Compliance: RΒ²=0.9986 indicates excellent adherence to Zipf's law
- High Frequency Dominance: Top 100 words cover 27.5% of corpus
- Long Tail: 810,443 words needed for remaining 28.6% 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 | 0.7762 π | 0.3424 | N/A | N/A |
| mono_64d | 64 | 0.7460 | 0.2848 | N/A | N/A |
| mono_128d | 128 | 0.6617 | 0.2475 | N/A | N/A |
| aligned_32d | 32 | 0.7762 | 0.3486 | 0.2660 | 0.6020 |
| aligned_64d | 64 | 0.7460 | 0.2779 | 0.4740 | 0.8420 |
| aligned_128d | 128 | 0.6617 | 0.2466 | 0.5920 | 0.8620 |
Key Findings
- Best Isotropy: mono_32d with 0.7762 (more uniform distribution)
- Semantic Density: Average pairwise similarity of 0.2913. Lower values indicate better semantic separation.
- Alignment Quality: Aligned models achieve up to 59.2% 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 | 0.588 | 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 |
skΓ‘kaΕ₯, skeptika, spiΕ‘kΓ‘ |
-a |
aiolskΓ©ho, augie, avermaet |
-p |
pygmejskΓ½ch, pozlovice, plouich |
-m |
malΓ‘rovej, medvΔdskej, maltskΓ©mu |
-k |
konkubΓnou, kolomajstrovstvΓ‘, krampovΓ‘ |
-ma |
malΓ‘rovej, maltskΓ©mu, marjinke |
-b |
bacteroidetes, belanskΓ©ho, bonsanto |
-d |
dagestanskΓ©ho, devoluΔnΓΊ, dorsey |
Productive Suffixes
| Suffix | Examples |
|---|---|
-a |
translokΓ‘cia, skeptika, holocephalimorpha |
-e |
wace, augie, pozlovice |
-i |
zapnutΓ½mi, accorsi, temetΕi |
-u |
konkubΓnou, tereziΓ‘nsku, aαΊu |
-m |
Ε₯aΕΎenΓm, Γ‘bdΓ‘lΓm, diolom |
-ch |
pygmejskΓ½ch, plouich, sturmbusch |
-o |
Ε‘tvorvrstvovΓ©ho, dagestanskΓ©ho, aiolskΓ©ho |
-ho |
Ε‘tvorvrstvovΓ©ho, dagestanskΓ©ho, aiolskΓ©ho |
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 |
|---|---|---|---|
ovan |
1.47x | 866 contexts | bovan, jovan, hovan |
ensk |
1.54x | 455 contexts | ΕΎenskΓ‘, jenskΓ‘, svensk |
vens |
1.99x | 101 contexts | ivens, svensk, civens |
iest |
1.70x | 184 contexts | piest, diest, siest |
stre |
1.40x | 457 contexts | astre, stret, stres |
hΓ‘dz |
1.69x | 150 contexts | hΓ‘dzal, hΓ‘dzaΕ₯, hΓ‘dzanΓ½ |
ranc |
1.56x | 223 contexts | ranco, rancy, rance |
emen |
1.43x | 352 contexts | zemen, hemen, femen |
nost |
1.57x | 197 contexts | anost, noste, cnosti |
enci |
1.54x | 179 contexts | nenci, ΕΎenci, benci |
Γ‘dza |
1.41x | 257 contexts | hrΓ‘dza, sΓ‘dzaΕ₯, zvΓ‘dza |
chΓ‘d |
1.50x | 85 contexts | chΓ‘dΕΎa, chΓ‘dim, nachΓ‘da |
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 |
-a |
106 words | poczesna, pesera |
-p |
-e |
78 words | paleozoologie, pernidae |
-s |
-e |
77 words | slintaΔke, strategiaage |
-p |
-m |
76 words | plΓ©nom, perlmutterom |
-p |
-u |
71 words | poΕ‘krabaniu, poisΕ₯ovΕou |
-s |
-a |
63 words | skia, spela |
-p |
-i |
61 words | parlamentami, pΓ‘ni |
-k |
-a |
61 words | krajΔoviΔkatarΓna, kodaka |
-m |
-a |
57 words | mulatta, matola |
-b |
-a |
51 words | biljana, burna |
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 |
|---|---|---|---|
| ΕΎeljezniΔar | ΕΎeljezniΔ-a-r |
7.5 | a |
| zawistowski | zawistows-k-i |
7.5 | k |
| fralignes | fralig-ne-s |
7.5 | ne |
| stromΔekom | stromΔe-k-om |
7.5 | k |
| dvojzΓ‘prah | dvojzΓ‘pr-a-h |
7.5 | a |
| textΓΊrovΓ© | textΓΊr-ov-Γ© |
6.0 | textΓΊr |
| turgenevovej | turgenev-ov-ej |
6.0 | turgenev |
| fulbrightova | fulbright-ov-a |
6.0 | fulbright |
| neohraniΔenΓ©ho | ne-ohraniΔenΓ©-ho |
6.0 | ohraniΔenΓ© |
| finΓ‘lovou | finΓ‘l-ov-ou |
6.0 | finΓ‘l |
| miroslavov | miroslav-ov |
4.5 | miroslav |
| josephina | josephi-na |
4.5 | josephi |
| englewoode | englewood-e |
4.5 | englewood |
| flindersa | flinders-a |
4.5 | flinders |
| wheatleya | wheatley-a |
4.5 | wheatley |
6.6 Linguistic Interpretation
Automated Insight: The language Slovak 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 (4.62x) |
| N-gram | 2-gram | Lowest perplexity (436) |
| Markov | Context-4 | Highest predictability (95.8%) |
| 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 02:39:37



















