Old English - Wikilangs Models
Comprehensive Research Report & Full Ablation Study
This repository contains NLP models trained and evaluated by Wikilangs, specifically on Old English 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 | 3.107x | 3.11 | 0.0859% | 252,634 |
| 16k | 3.441x | 3.45 | 0.0951% | 228,129 |
| 32k | 3.763x | 3.77 | 0.1040% | 208,636 |
| 64k | 4.012x π | 4.02 | 0.1109% | 195,650 |
Tokenization Examples
Below are sample sentences tokenized with each vocabulary size:
Sample 1: GrΔat ColdΕ«n () is ΓΎorp in ΓΎΓ¦m East Γriding, se is EoferΖΏicscire dΗ£l, on Englum....
| Vocab | Tokens | Count |
|---|---|---|
| 8k | βgrΔat βc old Ε«n β() βis βΓΎorp βin βΓΎΓ¦m βeast ... (+15 more) |
25 |
| 16k | βgrΔat βc old Ε«n β() βis βΓΎorp βin βΓΎΓ¦m βeast ... (+15 more) |
25 |
| 32k | βgrΔat βcold Ε«n β() βis βΓΎorp βin βΓΎΓ¦m βeast βΓΎriding ... (+14 more) |
24 |
| 64k | βgrΔat βcold Ε«n β() βis βΓΎorp βin βΓΎΓ¦m βeast βΓΎriding ... (+14 more) |
24 |
Sample 2: Lingua Franca Nova is gehugod sprΗ£c. Utweardlice bendas elefen.org gereord
| Vocab | Tokens | Count |
|---|---|---|
| 8k | βl ing ua βfranc a βnov a βis βgeh ug ... (+11 more) |
21 |
| 16k | βl ing ua βfranc a βnova βis βgeh ug od ... (+10 more) |
20 |
| 32k | βling ua βfranca βnova βis βgehugod βsprΗ£c . βutweardlice βbendas ... (+5 more) |
15 |
| 64k | βlingua βfranca βnova βis βgehugod βsprΗ£c . βutweardlice βbendas βele ... (+4 more) |
14 |
Sample 3: Andreas IΗ£xcΕ«n ΖΏΓ¦s se seofoΓ°a Foresittend ΓΎΔra GeΔnlΗ£htra RΔ«ca, fram ΓΎΗ£m gΔare Ε...
| Vocab | Tokens | Count |
|---|---|---|
| 8k | βandreas βi Η£ x c Ε«n βΖΏΓ¦s βse βseof oΓ°a ... (+17 more) |
27 |
| 16k | βandreas βiΗ£x c Ε«n βΖΏΓ¦s βse βseofoΓ°a βforesittend βΓΎΔra βgeΔnlΗ£htra ... (+14 more) |
24 |
| 32k | βandreas βiΗ£x c Ε«n βΖΏΓ¦s βse βseofoΓ°a βforesittend βΓΎΔra βgeΔnlΗ£htra ... (+14 more) |
24 |
| 64k | βandreas βiΗ£xcΕ«n βΖΏΓ¦s βse βseofoΓ°a βforesittend βΓΎΔra βgeΔnlΗ£htra βrΔ«ca , ... (+12 more) |
22 |
Key Findings
- Best Compression: 64k achieves 4.012x compression
- Lowest UNK Rate: 8k with 0.0859% 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 | 3,551 | 11.79 | 7,095 | 21.2% | 53.1% |
| 2-gram | Subword | 365 π | 8.51 | 3,006 | 61.0% | 98.1% |
| 3-gram | Word | 3,411 | 11.74 | 6,128 | 21.1% | 50.1% |
| 3-gram | Subword | 3,332 | 11.70 | 23,711 | 22.3% | 62.8% |
| 4-gram | Word | 6,747 | 12.72 | 11,452 | 16.3% | 36.7% |
| 4-gram | Subword | 18,651 | 14.19 | 105,677 | 10.6% | 32.7% |
| 5-gram | Word | 4,718 | 12.20 | 8,067 | 18.6% | 41.3% |
| 5-gram | Subword | 56,790 | 15.79 | 217,768 | 6.4% | 20.2% |
Top 5 N-grams by Size
2-grams (Word):
| Rank | N-gram | Count |
|---|---|---|
| 1 | on ΓΎΗ£m |
784 |
| 2 | in ΓΎΗ£m |
762 |
| 3 | in ΓΎΓ¦m |
673 |
| 4 | of the |
645 |
| 5 | se is |
536 |
3-grams (Word):
| Rank | N-gram | Count |
|---|---|---|
| 1 | td valign top |
529 |
| 2 | ΓΎΓ¦s geΔnedan cynerΔ«ces |
312 |
| 3 | is ΓΎorp in |
311 |
| 4 | on eoferwicscΔ«re ΓΎΓ¦s |
248 |
| 5 | eoferwicscΔ«re ΓΎΓ¦s geΔnedan |
248 |
4-grams (Word):
| Rank | N-gram | Count |
|---|---|---|
| 1 | on eoferwicscΔ«re ΓΎΓ¦s geΔnedan |
248 |
| 2 | eoferwicscΔ«re ΓΎΓ¦s geΔnedan cynerΔ«ces |
248 |
| 3 | is eoferΖΏicscire dΗ£l on |
232 |
| 4 | eoferΖΏicscire dΗ£l on englum |
231 |
| 5 | se is eoferΖΏicscire dΗ£l |
229 |
5-grams (Word):
| Rank | N-gram | Count |
|---|---|---|
| 1 | on eoferwicscΔ«re ΓΎΓ¦s geΔnedan cynerΔ«ces |
248 |
| 2 | is eoferΖΏicscire dΗ£l on englum |
231 |
| 3 | se is eoferΖΏicscire dΗ£l on |
229 |
| 4 | ΓΎriding se is eoferΖΏicscire dΗ£l |
224 |
| 5 | east ΓΎriding se is eoferΖΏicscire |
170 |
2-grams (Subword):
| Rank | N-gram | Count |
|---|---|---|
| 1 | e _ |
68,542 |
| 2 | a n |
60,904 |
| 3 | n _ |
55,318 |
| 4 | s _ |
47,837 |
| 5 | n d |
40,759 |
3-grams (Subword):
| Rank | N-gram | Count |
|---|---|---|
| 1 | a n d |
24,396 |
| 2 | n d _ |
20,668 |
| 3 | a n _ |
16,952 |
| 4 | _ a n |
16,629 |
| 5 | o n _ |
16,182 |
4-grams (Subword):
| Rank | N-gram | Count |
|---|---|---|
| 1 | a n d _ |
16,673 |
| 2 | _ a n d |
14,847 |
| 3 | _ o n _ |
10,364 |
| 4 | _ i s _ |
10,180 |
| 5 | _ i n _ |
9,895 |
5-grams (Subword):
| Rank | N-gram | Count |
|---|---|---|
| 1 | _ a n d _ |
14,216 |
| 2 | _ t h e _ |
3,853 |
| 3 | _ ΓΎ Η£ m _ |
3,654 |
| 4 | _ ΓΎ Γ¦ s _ |
3,541 |
| 5 | _ h i s _ |
3,480 |
Key Findings
- Best Perplexity: 2-gram (subword) with 365
- Entropy Trend: Decreases with larger n-grams (more predictable)
- Coverage: Top-1000 patterns cover ~20% 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 | 0.6200 | 1.537 | 3.57 | 86,918 | 38.0% |
| 1 | Subword | 0.8434 | 1.794 | 6.43 | 1,235 | 15.7% |
| 2 | Word | 0.1550 | 1.113 | 1.30 | 307,624 | 84.5% |
| 2 | Subword | 0.9640 | 1.951 | 5.90 | 7,944 | 3.6% |
| 3 | Word | 0.0385 | 1.027 | 1.05 | 397,324 | 96.2% |
| 3 | Subword | 0.8649 | 1.821 | 4.02 | 46,823 | 13.5% |
| 4 | Word | 0.0127 π | 1.009 | 1.02 | 415,064 | 98.7% |
| 4 | Subword | 0.6219 | 1.539 | 2.55 | 188,154 | 37.8% |
Generated Text Samples (Word-based)
Below are text samples generated from each word-based Markov chain model:
Context Size 1:
and bedΓ¦ldede hine in ΓΎΗ£m geΔnedum rΔ«cum ΓΎΔ protest sang rocc and sΔ«ΓΎe hrΔΓ°cyninges hΔm toon francum in ΓΎΓ¦m miclum burgum and his ΖΏΓ¦ter hit hΓͺ hΓͺ willgesweostor shes laid backis unesco Γ¦fter dΓ©aΓ°e drepe ΓΎrΕΖΏade heorosΖΏeng heardn ond sΔo hΔafodmearc iesuitisces rΗ£ses it was f...
Context Size 2:
on ΓΎΗ£m fylle ΓΎΗ£m ΓΎe nΔhwæþer ne ΓΎΔ Δ‘eΔnedan land sculon ne Η£niΔ‘ land sceal Γ¦tfΕn oΓΎΓΎein ΓΎΗ£m indiscum lande uttar pradesh ΓΎΓ¦t land ΓΎΓ¦t ΖΏΓ¦s corΔan independence activist politicians and jo...in ΓΎΓ¦m east ΓΎriding se is eoferΖΏicscire dΗ£l on englum hit hΓ¦fΓΎ 11 351 bΕ«endas on eoferwicscΔ«re
Context Size 3:
td valign top ualentinianus ii td valign top td to 297 td valign top co emperor with honoriusis ΓΎorp in soria on castile and leΓ³ne in spΔonlande and ΓΎorpas on sorieeoferwicscΔ«re ΓΎΓ¦s geΔnedan cynerΔ«ces and hΔafodman ΓΎΓ¦s behealdenda hΔapes siΓΎΓ°an mΗ£dmΕnaΓΎ he is gebΔ...
Context Size 4:
on eoferwicscΔ«re ΓΎΓ¦s geΔnedan cynerΔ«cesis eoferΖΏicscire dΗ£l on englalande on eoferwicscΔ«re ΓΎΓ¦s geΔnedan cynerΔ«ceseoferΖΏicscire dΗ£l on englum mid grΔatum hΗ£ΓΎfelda Δ‘esΔieppaΓΎ hie ΓΎone burgsΔipe of hΗ£ΓΎfelda on eoferw...
Generated Text Samples (Subword-based)
Below are text samples generated from each subword-based Markov chain model:
Context Size 1:
_htofunes_anΕre_e_c_weaΓΎΗ£fyn_scan_ΓΎeal_wun_berie
Context Size 2:
e_of_fi_94oΓ°be_twan_thoseadand_Δ«egn_nΔ«ΖΏ_mesprytt,_ΓΎ
Context Size 3:
and_und_ofher_mΔ_snd_titutede_him._han_asscran_betwa_Η£
Context Size 4:
and_belalan_(mother_and_Δ‘ecosta_tΖΏiste_on_ΓΎΔ_habbaΓ°_nofgo
Key Findings
- Best Predictability: Context-4 (word) with 98.7% predictability
- Branching Factor: Decreases with context size (more deterministic)
- Memory Trade-off: Larger contexts require more storage (188,154 contexts)
- Recommendation: Context-3 or Context-4 for text generation
4. Vocabulary Analysis
Statistics
| Metric | Value |
|---|---|
| Vocabulary Size | 31,186 |
| Total Tokens | 403,003 |
| Mean Frequency | 12.92 |
| Median Frequency | 3 |
| Frequency Std Dev | 156.70 |
Most Common Words
| Rank | Word | Frequency |
|---|---|---|
| 1 | and | 14,299 |
| 2 | on | 10,683 |
| 3 | is | 10,302 |
| 4 | in | 10,147 |
| 5 | of | 6,062 |
| 6 | se | 4,316 |
| 7 | the | 3,973 |
| 8 | ΓΎΗ£m | 3,669 |
| 9 | ΓΎΓ¦s | 3,610 |
| 10 | his | 3,501 |
Least Common Words (from vocabulary)
| Rank | Word | Frequency |
|---|---|---|
| 1 | minga | 2 |
| 2 | blæcfugolond | 2 |
| 3 | ΖΏΔ«leacstede | 2 |
| 4 | cΕcsΔΔ«re | 2 |
| 5 | winnebagsΔΔ«re | 2 |
| 6 | Γ¦lfrΔdingtΕ«n | 2 |
| 7 | irfung | 2 |
| 8 | larΔodo | 2 |
| 9 | grΕndΔ | 2 |
| 10 | dΗ£lungs | 2 |
Zipf's Law Analysis
| Metric | Value |
|---|---|
| Zipf Coefficient | 0.9344 |
| RΒ² (Goodness of Fit) | 0.998034 |
| Adherence Quality | excellent |
Coverage Analysis
| Top N Words | Coverage |
|---|---|
| Top 100 | 38.0% |
| Top 1,000 | 59.6% |
| Top 5,000 | 77.9% |
| Top 10,000 | 86.2% |
Key Findings
- Zipf Compliance: RΒ²=0.9980 indicates excellent adherence to Zipf's law
- High Frequency Dominance: Top 100 words cover 38.0% of corpus
- Long Tail: 21,186 words needed for remaining 13.8% coverage
5. Word Embeddings Evaluation
5.1 Cross-Lingual Alignment
5.2 Model Comparison
| Model | Dimension | Isotropy | Semantic Density | Alignment R@1 | Alignment R@10 |
|---|---|---|---|---|---|
| mono_32d | 32 | 0.7896 | 0.3585 | N/A | N/A |
| mono_64d | 64 | 0.4746 | 0.3175 | N/A | N/A |
| mono_128d | 128 | 0.1353 | 0.3004 | N/A | N/A |
| aligned_32d | 32 | 0.7896 π | 0.3555 | 0.0300 | 0.2480 |
| aligned_64d | 64 | 0.4746 | 0.3090 | 0.0860 | 0.3400 |
| aligned_128d | 128 | 0.1353 | 0.3041 | 0.1280 | 0.4020 |
Key Findings
- Best Isotropy: aligned_32d with 0.7896 (more uniform distribution)
- Semantic Density: Average pairwise similarity of 0.3242. Lower values indicate better semantic separation.
- Alignment Quality: Aligned models achieve up to 12.8% 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 | 1.044 | 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 |
|---|---|
-ge |
geondrΔ«cisce, gebold, gemyndgung |
Productive Suffixes
| Suffix | Examples |
|---|---|
-e |
ΔrwurΓ°nysse, cΗ£Δ‘e, farende |
-s |
celebrations, villages, annivs |
-es |
villages, ides, missiles |
-an |
ΓΎΔodacynewΔ«san, hΔligan, europiscan |
-um |
dorsΓ¦tum, maniΘum, elpendum |
-de |
farende, ungeΖΏilde, bestandende |
-en |
ΖΏriten, eΔΔ‘en, hyrneΔ‘en |
-on |
edmonton, huffington, aragon |
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 |
|---|---|---|---|
enne |
2.04x | 48 contexts | fenne, etenne, cenneΓΎ |
mani |
2.03x | 43 contexts | amani, maniΘ, maniΔ‘ |
wear |
1.91x | 43 contexts | wearΓ°, wearg, weard |
ster |
1.67x | 59 contexts | sister, Δaster, faster |
unge |
1.77x | 46 contexts | tunge, tunges, jungen |
tion |
2.19x | 19 contexts | motion, nation, action |
inga |
1.72x | 34 contexts | ΓΎinga, minga, Γ°inga |
ning |
1.64x | 35 contexts | mining, cining, cyning |
aste |
1.69x | 27 contexts | taste, easte, Δaste |
ynin |
2.21x | 11 contexts | cynin, cyning, cyninΘ |
afod |
1.82x | 18 contexts | hΔafod, heafod, ΖΏafode |
nisc |
1.49x | 27 contexts | rΕ«nisc, denisc, dΔnisc |
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 |
|---|---|---|---|
-ge |
-e |
79 words | geΖΏorhte, geΖΏΗ£re |
-ge |
-en |
35 words | getimbroden, geferræden |
-ge |
-de |
35 words | geanede, gehiersomode |
-ge |
-s |
29 words | genus, geardas |
-ge |
-an |
20 words | gegildan, gemæccan |
-ge |
-um |
20 words | gerΔdum, germanicum |
-ge |
-es |
17 words | geofones, geΔnlΗ£htes |
-ge |
-on |
9 words | gestaΓ°oledon, gestrΔon |
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 |
|---|---|---|---|
| gehΖΏilcum | ge-hΖΏilc-um |
6.0 | hΖΏilc |
| gefeahten | ge-feaht-en |
6.0 | feaht |
| underbyrigum | underbyrig-um |
4.5 | underbyrig |
| geΓΎoftscipe | ge-ΓΎoftscipe |
4.5 | ΓΎoftscipe |
| sanghordes | sanghord-es |
4.5 | sanghord |
| gesweoster | ge-sweoster |
4.5 | sweoster |
| russlandes | russland-es |
4.5 | russland |
| ΓΎΔodisclandes | ΓΎΔodiscland-es |
4.5 | ΓΎΔodiscland |
| gestrΔonum | ge-strΔ-on-um |
4.5 | strΔ |
| drΘ³Δ‘elandes | drΘ³Δ‘eland-es |
4.5 | drΘ³Δ‘eland |
| drΔamhordes | drΔamhord-es |
4.5 | drΔamhord |
| andweardum | andweard-um |
4.5 | andweard |
| engliscan | englisc-an |
4.5 | englisc |
| stΗ£rlican | stΗ£rlic-an |
4.5 | stΗ£rlic |
| bedæleden | bedæled-en |
4.5 | bedæled |
6.6 Linguistic Interpretation
Automated Insight: The language Old English 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 (4.01x) |
| N-gram | 2-gram | Lowest perplexity (365) |
| Markov | Context-4 | Highest predictability (98.7%) |
| 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: 2026-01-03 16:22:13



















