Finnish - Wikilangs Models
Comprehensive Research Report & Full Ablation Study
This repository contains NLP models trained and evaluated by Wikilangs, specifically on Finnish 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 | 3.799x | 3.80 | 0.1369% | 3,461,300 |
| 16k | 4.273x | 4.27 | 0.1539% | 3,077,483 |
| 32k | 4.760x | 4.76 | 0.1714% | 2,763,001 |
| 64k | 5.221x π | 5.22 | 0.1881% | 2,518,757 |
Tokenization Examples
Below are sample sentences tokenized with each vocabulary size:
Sample 1: LΓ€hteet judokat olympiamitalistit syntyneet henkilΓΆt
| Vocab | Tokens | Count |
|---|---|---|
| 8k | βlΓ€hteet βjud ok at βolympiamital istit βsyntyneet βhenkilΓΆt |
8 |
| 16k | βlΓ€hteet βjud ok at βolympiamital istit βsyntyneet βhenkilΓΆt |
8 |
| 32k | βlΓ€hteet βjud ok at βolympiamital istit βsyntyneet βhenkilΓΆt |
8 |
| 64k | βlΓ€hteet βjud okat βolympiamital istit βsyntyneet βhenkilΓΆt |
7 |
Sample 2: Tapahtumia Anicetus vastaanotti paavin viran. SyntyneitΓ€ Chang Tao Ling, taolain...
| Vocab | Tokens | Count |
|---|---|---|
| 8k | βtapahtumia βan ic et us βvastaan otti βpaa vin βviran ... (+16 more) |
26 |
| 16k | βtapahtumia βan ic et us βvastaan otti βpaavin βviran . ... (+14 more) |
24 |
| 32k | βtapahtumia βan ic etus βvastaanotti βpaavin βviran . βsyntyneitΓ€ βchang ... (+11 more) |
21 |
| 64k | βtapahtumia βan ic etus βvastaanotti βpaavin βviran . βsyntyneitΓ€ βchang ... (+9 more) |
19 |
Sample 3: Los RΓos on yksi Ecuadorin 24 maakunnasta. Sen pÀÀkaupunki on Babahoyo, pinta-al...
| Vocab | Tokens | Count |
|---|---|---|
| 8k | βlos βr Γ os βon βyksi βec ua dor in ... (+43 more) |
53 |
| 16k | βlos βr Γ os βon βyksi βec ua dorin β ... (+41 more) |
51 |
| 32k | βlos βr Γ os βon βyksi βecua dorin β 2 ... (+38 more) |
48 |
| 64k | βlos βr Γ os βon βyksi βecuadorin β 2 4 ... (+37 more) |
47 |
Key Findings
- Best Compression: 64k achieves 5.221x compression
- Lowest UNK Rate: 8k with 0.1369% 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 | 468,139 | 18.84 | 3,042,410 | 6.0% | 13.9% |
| 2-gram | Subword | 278 π | 8.12 | 22,535 | 67.1% | 99.2% |
| 3-gram | Word | 1,065,692 | 20.02 | 4,275,337 | 4.6% | 9.6% |
| 3-gram | Subword | 2,642 | 11.37 | 185,096 | 22.8% | 69.4% |
| 4-gram | Word | 2,274,790 | 21.12 | 6,954,562 | 3.3% | 7.6% |
| 4-gram | Subword | 17,026 | 14.06 | 1,194,419 | 9.7% | 35.2% |
| 5-gram | Word | 1,753,957 | 20.74 | 4,818,809 | 2.9% | 7.7% |
| 5-gram | Subword | 77,677 | 16.25 | 4,549,709 | 5.0% | 20.0% |
Top 5 N-grams by Size
2-grams (Word):
| Rank | N-gram | Count |
|---|---|---|
| 1 | aiheesta muualla |
249,855 |
| 2 | kitt peak |
206,017 |
| 3 | peak spacewatch |
204,244 |
| 4 | lΓ€hteet aiheesta |
179,493 |
| 5 | mount lemmon |
164,266 |
3-grams (Word):
| Rank | N-gram | Count |
|---|---|---|
| 1 | kitt peak spacewatch |
204,244 |
| 2 | lΓ€hteet aiheesta muualla |
179,390 |
| 3 | mt lemmon survey |
67,208 |
| 4 | lemmon mt lemmon |
67,205 |
| 5 | mount lemmon mt |
67,205 |
4-grams (Word):
| Rank | N-gram | Count |
|---|---|---|
| 1 | mount lemmon mt lemmon |
67,205 |
| 2 | lemmon mt lemmon survey |
67,205 |
| 3 | lemmon mount lemmon survey |
48,518 |
| 4 | mount lemmon mount lemmon |
48,517 |
| 5 | haleakala pan starrs 1 |
41,305 |
5-grams (Word):
| Rank | N-gram | Count |
|---|---|---|
| 1 | mount lemmon mt lemmon survey |
67,205 |
| 2 | mount lemmon mount lemmon survey |
48,517 |
| 3 | lokakuuta mount lemmon mt lemmon |
12,734 |
| 4 | syyskuuta mount lemmon mt lemmon |
9,683 |
| 5 | 0 0 0 0 0 |
9,576 |
2-grams (Subword):
| Rank | N-gram | Count |
|---|---|---|
| 1 | n _ |
35,431,794 |
| 2 | a _ |
28,224,764 |
| 3 | e n |
20,320,601 |
| 4 | i n |
18,392,995 |
| 5 | t a |
18,015,565 |
3-grams (Subword):
| Rank | N-gram | Count |
|---|---|---|
| 1 | e n _ |
11,913,920 |
| 2 | i n _ |
7,559,259 |
| 3 | a n _ |
6,328,547 |
| 4 | t a _ |
6,095,039 |
| 5 | j a _ |
5,873,170 |
4-grams (Subword):
| Rank | N-gram | Count |
|---|---|---|
| 1 | _ j a _ |
4,688,853 |
| 2 | s s a _ |
3,594,453 |
| 3 | n e n _ |
2,793,972 |
| 4 | _ o n _ |
2,528,919 |
| 5 | s t a _ |
2,335,812 |
5-grams (Subword):
| Rank | N-gram | Count |
|---|---|---|
| 1 | i n e n _ |
2,066,240 |
| 2 | k u u t a |
1,605,934 |
| 3 | u u t a _ |
1,591,336 |
| 4 | a _ j a _ |
1,344,019 |
| 5 | _ o l i _ |
1,224,801 |
Key Findings
- Best Perplexity: 2-gram (subword) with 278
- 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 | 0.9729 | 1.963 | 11.25 | 5,006,345 | 2.7% |
| 1 | Subword | 1.1405 | 2.205 | 8.17 | 12,030 | 0.0% |
| 2 | Word | 0.2871 | 1.220 | 1.85 | 56,234,784 | 71.3% |
| 2 | Subword | 0.6527 | 1.572 | 4.40 | 98,107 | 34.7% |
| 3 | Word | 0.0982 | 1.070 | 1.20 | 104,064,802 | 90.2% |
| 3 | Subword | 0.7699 | 1.705 | 4.59 | 431,251 | 23.0% |
| 4 | Word | 0.0383 π | 1.027 | 1.07 | 124,192,112 | 96.2% |
| 4 | Subword | 0.7445 | 1.675 | 3.90 | 1,979,645 | 25.5% |
Generated Text Samples (Word-based)
Below are text samples generated from each word-based Markov chain model:
Context Size 1:
ja qing dynastioiden 11 6 h f girolamo savonarolalta hellinckin poika golden age animaatioelokuvissa...on yhdysvaltalainen rattikelkkailija william diller yhdysvaltalainen ooppera tampereen klassillisest...oli sitten valmistui vuonna kuningas arthuriin venΓ€jΓ€n tiedeakatemia isΓ€nnΓΆi toisen sijan koko heimo...
Context Size 2:
aiheesta muualla albumit albumit crissin albumitkitt peak spacewatch dy6 16 maaliskuuta socorro linear fs36 18 maaliskuuta oslossa miesten kalenteri...peak spacewatch tl36 12 lokakuuta charles nunzio joka aloitti lΓ€hetyksensΓ€ 18 huhtikuuta kapkaupunki...
Context Size 3:
kitt peak spacewatch tym xa58 4 tammikuuta tincana m kusiak m ΕΌoΕnowsk aq12 5 lokakuuta kitt peak sp...lΓ€hteet aiheesta muualla piirikunnat kartli pl chaszurimt lemmon survey yz11 17 tammikuuta haleakala pan starrs 1 17 lokakuuta mount lemmon mount lemmon su...
Context Size 4:
lemmon mt lemmon survey sv65 21 syyskuuta mount lemmon mount lemmon survey 22 toukokuuta wise wise k...mount lemmon mt lemmon survey vv 8 marraskuuta mayhill mayhill vd8 8 marraskuuta catalina css 14 tou...lemmon mount lemmon survey 8 tammikuuta mount lemmon mt lemmon survey fk38 28 maaliskuuta kitt peak ...
Generated Text Samples (Subword-based)
Below are text samples generated from each subword-based Markov chain model:
Context Size 1:
_hΓ€tionewone_β_rapuuikikakeniipoin_sentalisaline
Context Size 2:
n_outehiaan_taan,a_1_kuusopirthreden_pilΓΆys._kerumi
Context Size 3:
en_eze._brit_dimikin_sureisi_lan_βtjan_koin_(s._29._ta
Context Size 4:
_ja_myΓΆs_aren_regiossa_101,56_metriΓ€_lnen_tuottana._vuott
Key Findings
- Best Predictability: Context-4 (word) with 96.2% predictability
- Branching Factor: Decreases with context size (more deterministic)
- Memory Trade-off: Larger contexts require more storage (1,979,645 contexts)
- Recommendation: Context-3 or Context-4 for text generation
4. Vocabulary Analysis
Statistics
| Metric | Value |
|---|---|
| Vocabulary Size | 2,250,455 |
| Total Tokens | 145,574,709 |
| Mean Frequency | 64.69 |
| Median Frequency | 4 |
| Frequency Std Dev | 4199.88 |
Most Common Words
| Rank | Word | Frequency |
|---|---|---|
| 1 | ja | 4,696,959 |
| 2 | on | 2,545,540 |
| 3 | oli | 1,230,343 |
| 4 | hΓ€n | 1,028,773 |
| 5 | vuonna | 905,604 |
| 6 | 1 | 689,784 |
| 7 | myΓΆs | 653,305 |
| 8 | s | 616,597 |
| 9 | 2 | 541,496 |
| 10 | lΓ€hteet | 519,252 |
Least Common Words (from vocabulary)
| Rank | Word | Frequency |
|---|---|---|
| 1 | navkatin | 2 |
| 2 | xovosista | 2 |
| 3 | sauvagetin | 2 |
| 4 | bundΕΎikatin | 2 |
| 5 | keltaevΓ€kuukala | 2 |
| 6 | glΓ€djekΓ€llan | 2 |
| 7 | wydlerin | 2 |
| 8 | joshualla | 2 |
| 9 | charmatzn | 2 |
| 10 | kidugala | 2 |
Zipf's Law Analysis
| Metric | Value |
|---|---|
| Zipf Coefficient | 0.9214 |
| RΒ² (Goodness of Fit) | 0.998159 |
| Adherence Quality | excellent |
Coverage Analysis
| Top N Words | Coverage |
|---|---|
| Top 100 | 21.8% |
| Top 1,000 | 41.3% |
| Top 5,000 | 57.6% |
| Top 10,000 | 64.9% |
Key Findings
- Zipf Compliance: RΒ²=0.9982 indicates excellent adherence to Zipf's law
- High Frequency Dominance: Top 100 words cover 21.8% of corpus
- Long Tail: 2,240,455 words needed for remaining 35.1% 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 | 0.7459 | 0.3486 | N/A | N/A |
| mono_64d | 64 | 0.7204 | 0.2821 | N/A | N/A |
| mono_128d | 128 | 0.6228 | 0.2311 | N/A | N/A |
| aligned_32d | 32 | 0.7459 π | 0.3499 | 0.3560 | 0.7800 |
| aligned_64d | 64 | 0.7204 | 0.2899 | 0.5740 | 0.8760 |
| aligned_128d | 128 | 0.6228 | 0.2356 | 0.7020 | 0.9140 |
Key Findings
- Best Isotropy: aligned_32d with 0.7459 (more uniform distribution)
- Semantic Density: Average pairwise similarity of 0.2895. Lower values indicate better semantic separation.
- Alignment Quality: Aligned models achieve up to 70.2% 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 | -0.615 | 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 |
|---|---|
-s |
sorapohjille, suus, suolamminpuro |
-a |
asiakkuuksien, anregungen, anglosaksissa |
-k |
kanadansuomalaiset, kotitaloustyΓΆntekijΓΆiden, kampanjoimalla |
-t |
taskilassa, tehostuu, tujh |
-p |
puhalluksen, pantaisiin, poismeno |
-m |
mq, mΓ€nnistΓΆnpolun, miehittΓ€jΓ€valtioiden |
-e |
eddarunoutta, everst, edsevΓΆ |
-b |
boeingillΓ€, bratslavista, bundille |
Productive Suffixes
| Suffix | Examples |
|---|---|
-n |
puhalluksen, asiakkuuksien, anregungen |
-a |
anglosaksissa, taskilassa, unimatka |
-en |
puhalluksen, asiakkuuksien, anregungen |
-in |
nΓ€yttelyihin, pantaisiin, tulviviin |
-ta |
bratslavista, todetuista, karstulasta |
-i |
darski, suolaiseksi, kuvernΓΆΓΆreiksi |
-sa |
anglosaksissa, taskilassa, nerjassa |
-an |
ulosteitaan, vallankumoustaan, apsaran |
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 |
|---|---|---|---|
ivat |
1.84x | 221 contexts | nivat, ivata, livat |
ttii |
1.81x | 221 contexts | ottii, uttiin, fΓ€ttii |
ises |
1.76x | 230 contexts | sises, isesi, rises |
tett |
1.36x | 562 contexts | tette, tetto, tettu |
staa |
1.45x | 361 contexts | staav, staar, staab |
ukse |
1.35x | 445 contexts | uksen, ukset, suksea |
sess |
1.58x | 144 contexts | sessa, sessi, sesso |
uome |
1.73x | 78 contexts | suome, luomen, luomea |
isuu |
1.65x | 85 contexts | fisuu, fisuun, paisuu |
Γ€ytt |
1.56x | 109 contexts | kΓ€yttΓ€, kΓ€ytto, nΓ€yttΓ€ |
tuks |
1.32x | 244 contexts | tuksu, tuksa, tuksi |
htee |
1.43x | 137 contexts | ahtee, yhteet, Γ€hteet |
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 |
|---|---|---|---|
-k |
-n |
338 words | kaksoisruokolehdykkΓ€soittimien, kyanzitthan |
-k |
-a |
304 words | kΓ€yttΓ€ytymisongelmia, karjalohja |
-s |
-n |
259 words | sisustusarkkitehtuurin, sallyyn |
-p |
-a |
236 words | paviaanista, polyamorisia |
-s |
-a |
228 words | sairausjaksoista, sponsoroinnista |
-m |
-n |
195 words | mamemon, mustionselΓ€n |
-p |
-n |
194 words | poweraden, puolueettomuuspolitiikkaan |
-t |
-n |
189 words | tΓ€yttΓ€miin, tieoikeuteen |
-t |
-a |
180 words | tutkalaitteella, tappioissa |
-m |
-a |
160 words | maeba, minisarjassa |
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 |
|---|---|---|---|
| pÀÀtoimessaan | pÀÀtoimes-sa-an |
7.5 | sa |
| nicolasia | nicola-si-a |
7.5 | si |
| seksiaiheisia | seksiaihei-si-a |
7.5 | si |
| elΓ€mΓ€nlangat | elΓ€mΓ€nlang-a-t |
7.5 | a |
| vauvanruokaa | vauvanruok-a-a |
7.5 | a |
| puuttunutkaan | puuttunutk-a-an |
7.5 | a |
| antenniverkkonsa | antenniverkko-n-sa |
7.5 | n |
| kirjoittamistaan | kirjoittamis-ta-an |
7.5 | ta |
| biogeenisiin | biogeeni-si-in |
7.5 | si |
| torppasivat | torppasiv-a-t |
7.5 | a |
| mediatoimijat | mediatoimij-a-t |
7.5 | a |
| artemΓsio | artemΓ-si-o |
7.5 | si |
| havaintoasemaa | havaintoasem-a-a |
7.5 | a |
| christΓ³foros | christΓ³for-o-s |
7.5 | o |
| porontiman | porontim-a-n |
7.5 | a |
6.6 Linguistic Interpretation
Automated Insight: The language Finnish 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 (5.22x) |
| N-gram | 2-gram | Lowest perplexity (278) |
| Markov | Context-4 | Highest predictability (96.2%) |
| 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: 2026-01-13 06:45:42



















