language: tn
language_name: Tswana
language_family: bantu_southern
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-bantu_southern
license: mit
library_name: wikilangs
pipeline_tag: text-generation
datasets:
- omarkamali/wikipedia-monthly
dataset_info:
name: wikipedia-monthly
description: Monthly snapshots of Wikipedia articles across 300+ languages
metrics:
- name: best_compression_ratio
type: compression
value: 4.812
- name: best_isotropy
type: isotropy
value: 0.8424
- name: vocabulary_size
type: vocab
value: 0
generated: 2026-01-11T00:00:00.000Z
Tswana - Wikilangs Models
Comprehensive Research Report & Full Ablation Study
This repository contains NLP models trained and evaluated by Wikilangs, specifically on Tswana 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 | 4.418x | 4.42 | 0.0556% | 737,223 |
| 16k | 4.593x | 4.59 | 0.0578% | 709,175 |
| 32k | 4.727x | 4.73 | 0.0595% | 689,022 |
| 64k | 4.812x 🏆 | 4.81 | 0.0606% | 676,881 |
Tokenization Examples
Below are sample sentences tokenized with each vocabulary size:
Sample 1: Need for Speed (NFS) ke motshameko wa motshikinyego o go thomiwang o o dirilweng...
| Vocab | Tokens | Count |
|---|---|---|
| 8k | ▁need ▁for ▁spe ed ▁( nf s ) ▁ke ▁motshameko ... (+22 more) |
32 |
| 16k | ▁need ▁for ▁spe ed ▁( nf s ) ▁ke ▁motshameko ... (+19 more) |
29 |
| 32k | ▁need ▁for ▁spe ed ▁( nf s ) ▁ke ▁motshameko ... (+19 more) |
29 |
| 64k | ▁need ▁for ▁speed ▁( nf s ) ▁ke ▁motshameko ▁wa ... (+17 more) |
27 |
Sample 2: Bekkersdal ke toropo ya Gauteng e ko lefatsheng la Aforika Borwa. Metswedi
| Vocab | Tokens | Count |
|---|---|---|
| 8k | ▁be k kers dal ▁ke ▁toropo ▁ya ▁gauteng ▁e ▁ko ... (+6 more) |
16 |
| 16k | ▁be k kers dal ▁ke ▁toropo ▁ya ▁gauteng ▁e ▁ko ... (+6 more) |
16 |
| 32k | ▁be k kers dal ▁ke ▁toropo ▁ya ▁gauteng ▁e ▁ko ... (+6 more) |
16 |
| 64k | ▁bekkersdal ▁ke ▁toropo ▁ya ▁gauteng ▁e ▁ko ▁lefatsheng ▁la ▁aforika ... (+3 more) |
13 |
Sample 3: Osaka ke toropo kgolo kwa Japan. E na le baagi ba le
| Vocab | Tokens | Count |
|---|---|---|
| 8k | ▁o saka ▁ke ▁toropo ▁kgolo ▁kwa ▁japan . ▁e ▁na ... (+4 more) |
14 |
| 16k | ▁o saka ▁ke ▁toropo ▁kgolo ▁kwa ▁japan . ▁e ▁na ... (+4 more) |
14 |
| 32k | ▁osaka ▁ke ▁toropo ▁kgolo ▁kwa ▁japan . ▁e ▁na ▁le ... (+3 more) |
13 |
| 64k | ▁osaka ▁ke ▁toropo ▁kgolo ▁kwa ▁japan . ▁e ▁na ▁le ... (+3 more) |
13 |
Key Findings
- Best Compression: 64k achieves 4.812x compression
- Lowest UNK Rate: 8k with 0.0556% 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 | 7,155 | 12.80 | 61,361 | 28.5% | 48.8% |
| 2-gram | Subword | 191 🏆 | 7.58 | 3,179 | 76.4% | 99.6% |
| 3-gram | Word | 14,210 | 13.79 | 120,191 | 25.9% | 38.6% |
| 3-gram | Subword | 1,323 | 10.37 | 26,297 | 38.5% | 81.3% |
| 4-gram | Word | 23,873 | 14.54 | 216,515 | 24.9% | 33.3% |
| 4-gram | Subword | 6,088 | 12.57 | 134,442 | 22.1% | 55.7% |
| 5-gram | Word | 10,743 | 13.39 | 157,061 | 32.2% | 39.1% |
| 5-gram | Subword | 18,500 | 14.18 | 344,305 | 15.2% | 39.9% |
Top 5 N-grams by Size
2-grams (Word):
| Rank | N-gram | Count |
|---|---|---|
| 1 | aforika borwa |
32,436 |
| 2 | toropo ya |
30,077 |
| 3 | ke toropo |
29,904 |
| 4 | ya gauteng |
29,770 |
| 5 | gauteng e |
29,736 |
3-grams (Word):
| Rank | N-gram | Count |
|---|---|---|
| 1 | ke toropo ya |
29,751 |
| 2 | ya gauteng e |
29,733 |
| 3 | gauteng e aforika |
29,718 |
| 4 | toropo ya gauteng |
29,718 |
| 5 | e aforika borwa |
29,717 |
4-grams (Word):
| Rank | N-gram | Count |
|---|---|---|
| 1 | ya gauteng e aforika |
29,718 |
| 2 | gauteng e aforika borwa |
29,717 |
| 3 | ke toropo ya gauteng |
29,716 |
| 4 | toropo ya gauteng e |
29,716 |
| 5 | mamelodi ke toropo ya |
29,700 |
5-grams (Word):
| Rank | N-gram | Count |
|---|---|---|
| 1 | ya gauteng e aforika borwa |
29,717 |
| 2 | ke toropo ya gauteng e |
29,714 |
| 3 | toropo ya gauteng e aforika |
29,706 |
| 4 | mamelodi ke toropo ya gauteng |
29,700 |
| 5 | borwa mamelodi ke toropo ya |
29,699 |
2-grams (Subword):
| Rank | N-gram | Count |
|---|---|---|
| 1 | a _ |
935,894 |
| 2 | e _ |
661,328 |
| 3 | o _ |
427,244 |
| 4 | l e |
283,587 |
| 5 | _ m |
267,742 |
3-grams (Subword):
| Rank | N-gram | Count |
|---|---|---|
| 1 | _ l e |
169,796 |
| 2 | l e _ |
163,890 |
| 3 | n g _ |
148,572 |
| 4 | w a _ |
147,301 |
| 5 | y a _ |
133,144 |
4-grams (Subword):
| Rank | N-gram | Count |
|---|---|---|
| 1 | _ y a _ |
122,807 |
| 2 | _ l e _ |
121,639 |
| 3 | e n g _ |
86,110 |
| 4 | _ g o _ |
81,757 |
| 5 | a _ b o |
80,508 |
5-grams (Subword):
| Rank | N-gram | Count |
|---|---|---|
| 1 | o _ y a _ |
65,761 |
| 2 | _ y a _ g |
42,726 |
| 3 | _ k w a _ |
39,822 |
| 4 | a _ g o _ |
37,584 |
| 5 | k a _ b o |
37,508 |
Key Findings
- Best Perplexity: 2-gram (subword) with 191
- Entropy Trend: Decreases with larger n-grams (more predictable)
- Coverage: Top-1000 patterns cover ~40% 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 | 0.9132 | 1.883 | 6.97 | 102,696 | 8.7% |
| 1 | Subword | 1.0155 | 2.022 | 7.94 | 975 | 0.0% |
| 2 | Word | 0.3523 | 1.277 | 2.10 | 714,400 | 64.8% |
| 2 | Subword | 0.9918 | 1.989 | 6.26 | 7,740 | 0.8% |
| 3 | Word | 0.1700 | 1.125 | 1.38 | 1,497,396 | 83.0% |
| 3 | Subword | 0.9000 | 1.866 | 4.58 | 48,443 | 10.0% |
| 4 | Word | 0.0886 🏆 | 1.063 | 1.16 | 2,060,334 | 91.1% |
| 4 | Subword | 0.6744 | 1.596 | 2.97 | 221,611 | 32.6% |
Generated Text Samples (Word-based)
Below are text samples generated from each word-based Markov chain model:
Context Size 1:
ya ntlha wa citylife ka beilby porteus bishopo wa batjho ba ba amegang mo melawaneng yale balatedi bale mo dipolelong tsa itsholelo le tlhaeletsano pula botswana e diragalang bonnyane le ...e aforika borwa mamelodi ke marang rang a le 357 quoting from the namibian via africabib
Context Size 2:
aforika borwa mamelodi ke toropo ya gauteng e aforika borwa mamelodi ke toropo ya gauteng e aforikatoropo ya gauteng e aforika borwa e tshwenyegile ka ditlamorago tse di nnang kwa kgaolong ya kwenengke toropo ya gauteng e aforika borwa mamelodi ke toropo ya gauteng e aforika borwa mamelodi ke
Context Size 3:
ke toropo ya gauteng e aforika borwa mamelodi ke toropo ya gauteng e aforika borwa mamelodi ke torop...ya gauteng e aforika borwa mamelodi ke toropo ya gauteng e aforika borwa mamelodi ke toropo ya gaute...toropo ya gauteng e aforika borwa mamelodi ke toropo ya gauteng e aforika borwa mamelodi ke toropo y...
Context Size 4:
ya gauteng e aforika borwa mamelodi ke toropo ya gauteng e aforika borwa mamelodi ke toropo ya gaute...toropo ya gauteng e aforika borwa mamelodi ke toropo ya gauteng e aforika borwa mamelodi ke toropo y...ke toropo ya gauteng e aforika borwa mamelodi ke toropo ya gauteng e aforika borwa mamelodi ke torop...
Generated Text Samples (Subword-based)
Below are text samples generated from each subword-based Markov chain model:
Context Size 1:
_tlanga_ssatllheasophopolotleshaeg,_ne_kgipave_d
Context Size 2:
a_mo_tlhabews_fete_neiratse_le_e_ko_tekgo_ke_e_bof_
Context Size 3:
_le_e_a_nna_e_tor_le_dipape_fa_tswa_ng_e_aforika_di_mo
Context Size 4:
_ya_borwa._mamelodi_le_mme_a_bonakgobaeng_of_ethiopia_re,
Key Findings
- Best Predictability: Context-4 (word) with 91.1% predictability
- Branching Factor: Decreases with context size (more deterministic)
- Memory Trade-off: Larger contexts require more storage (221,611 contexts)
- Recommendation: Context-3 or Context-4 for text generation
4. Vocabulary Analysis
Statistics
| Metric | Value |
|---|---|
| Vocabulary Size | 51,001 |
| Total Tokens | 3,021,722 |
| Mean Frequency | 59.25 |
| Median Frequency | 4 |
| Frequency Std Dev | 1394.66 |
Most Common Words
| Rank | Word | Frequency |
|---|---|---|
| 1 | ya | 122,910 |
| 2 | le | 122,280 |
| 3 | e | 120,451 |
| 4 | a | 105,517 |
| 5 | go | 82,599 |
| 6 | ka | 70,434 |
| 7 | ba | 60,026 |
| 8 | ne | 54,685 |
| 9 | o | 51,263 |
| 10 | ke | 50,884 |
Least Common Words (from vocabulary)
| Rank | Word | Frequency |
|---|---|---|
| 1 | komit | 2 |
| 2 | duduzane | 2 |
| 3 | marčetić | 2 |
| 4 | prijedor | 2 |
| 5 | dnevne | 2 |
| 6 | novosti | 2 |
| 7 | greifenseelauf | 2 |
| 8 | makithing | 2 |
| 9 | benet | 2 |
| 10 | linnen | 2 |
Zipf's Law Analysis
| Metric | Value |
|---|---|
| Zipf Coefficient | 1.1378 |
| R² (Goodness of Fit) | 0.995228 |
| Adherence Quality | excellent |
Coverage Analysis
| Top N Words | Coverage |
|---|---|
| Top 100 | 57.2% |
| Top 1,000 | 76.6% |
| Top 5,000 | 89.3% |
| Top 10,000 | 93.6% |
Key Findings
- Zipf Compliance: R²=0.9952 indicates excellent adherence to Zipf's law
- High Frequency Dominance: Top 100 words cover 57.2% of corpus
- Long Tail: 41,001 words needed for remaining 6.4% 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 | 0.8424 | 0.3285 | N/A | N/A |
| mono_64d | 64 | 0.8282 | 0.2689 | N/A | N/A |
| mono_128d | 128 | 0.7325 | 0.2225 | N/A | N/A |
| aligned_32d | 32 | 0.8424 🏆 | 0.3391 | 0.0640 | 0.3560 |
| aligned_64d | 64 | 0.8282 | 0.2702 | 0.1760 | 0.5100 |
| aligned_128d | 128 | 0.7325 | 0.2209 | 0.2840 | 0.6440 |
Key Findings
- Best Isotropy: aligned_32d with 0.8424 (more uniform distribution)
- Semantic Density: Average pairwise similarity of 0.2751. Lower values indicate better semantic separation.
- Alignment Quality: Aligned models achieve up to 28.4% 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 | -0.020 | 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 |
|---|---|
-ma |
marcia, mahlatse, magudumana |
-m |
moinjineere, marcia, membrane |
-s |
sejaneng, still, stratification |
-b |
bontshiwang, busiwa, bongz |
-a |
adaptations, ausi, aug |
-di |
diitsholelo, distinguished, dikhwaere |
-mo |
moinjineere, motlabogi, monkeybone |
-t |
thapisitsweng, thakanyo, tedx |
Productive Suffixes
| Suffix | Examples |
|---|---|
-e |
christine, ratilwe, legotlhe |
-ng |
sejaneng, thapisitsweng, bontshiwang |
-a |
otjozondjupa, zuma, marcia |
-g |
rosberg, sejaneng, thapisitsweng |
-s |
vermeers, adaptations, focuses |
-o |
diitsholelo, phatlalatso, thakanyo |
-n |
zeaxanthin, stratification, defection |
-i |
shwahili, ausi, cpi |
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 |
|---|---|---|---|
tion |
2.63x | 39 contexts | action, motion, notion |
tsen |
2.13x | 60 contexts | tseno, tsene, tsena |
tlho |
1.79x | 96 contexts | tlhoa, tlhopo, tlhora |
tshw |
2.08x | 46 contexts | tshwa, ntshwa, tshweu |
otlh |
1.78x | 67 contexts | otlhe, yotlhe, sotlhe |
tshe |
1.76x | 68 contexts | ntshe, tsheko, tshele |
lhop |
2.30x | 24 contexts | tlhopo, tlhopa, tlhopha |
otsw |
1.86x | 43 contexts | otswa, rotswe, motswe |
hoph |
2.25x | 21 contexts | tlhopha, tlhopho, tlhophe |
mets |
1.81x | 43 contexts | metso, metsi, metse |
wana |
1.98x | 30 contexts | swana, mowana, ntwana |
gwag |
2.28x | 18 contexts | ngwag, gwaga, ngwago |
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 |
|---|---|---|---|
-t |
-g |
121 words | tlhodileng, tlileng |
-t |
-ng |
120 words | tlhodileng, tlileng |
-t |
-a |
111 words | tshwaetswa, tsenngwa |
-t |
-e |
108 words | takirambudde, togolese |
-s |
-e |
95 words | setswerre, segololwane |
-b |
-i |
93 words | bogasi, bukhari |
-b |
-e |
90 words | blaze, banyamulenge |
-di |
-o |
84 words | ditshenolo, dikago |
-b |
-g |
83 words | benefitting, buang |
-b |
-ng |
81 words | benefitting, buang |
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 |
|---|---|---|---|
| botshepegi | botshepe-g-i |
7.5 | g |
| kgatlhego | kgatlhe-g-o |
7.5 | g |
| prehistoric | p-re-historic |
7.5 | historic |
| watergate | water-ga-te |
7.5 | ga |
| eletsegang | eletseg-a-ng |
7.5 | a |
| malahlela | malah-le-la |
7.5 | le |
| botswanago | botswana-g-o |
7.5 | g |
| ditlhagala | ditlhag-a-la |
7.5 | a |
| motshidisi | motshi-di-si |
7.5 | di |
| bosimegeng | bosimeg-e-ng |
7.5 | e |
| northeast | northea-s-t |
7.5 | s |
| diphethogo | diphetho-g-o |
7.5 | g |
| rwandaise | rwanda-i-se |
7.5 | i |
| utlwaleng | utlwa-le-ng |
7.5 | le |
| kgatlhile | kgatlh-i-le |
7.5 | i |
6.6 Linguistic Interpretation
Automated Insight: The language Tswana shows high morphological productivity. The subword models are significantly more efficient than word models, suggesting a rich system of affixation or compounding.
7. Summary & Recommendations
Production Recommendations
| Component | Recommended | Rationale |
|---|---|---|
| Tokenizer | 64k BPE | Best compression (4.81x) |
| N-gram | 2-gram | Lowest perplexity (191) |
| Markov | Context-4 | Highest predictability (91.1%) |
| Embeddings | 100d | Balanced semantic capture and isotropy |
Appendix: Metrics Glossary & Interpretation Guide
This section provides definitions, intuitions, and guidance for interpreting the metrics used throughout this report.
Tokenizer Metrics
Compression Ratio
Definition: The ratio of characters to tokens (chars/token). Measures how efficiently the tokenizer represents text.
Intuition: Higher compression means fewer tokens needed to represent the same text, reducing sequence lengths for downstream models. A 3x compression means ~3 characters per token on average.
What to seek: Higher is generally better for efficiency, but extremely high compression may indicate overly aggressive merging that loses morphological information.
Average Token Length (Fertility)
Definition: Mean number of characters per token produced by the tokenizer.
Intuition: Reflects the granularity of tokenization. Longer tokens capture more context but may struggle with rare words; shorter tokens are more flexible but increase sequence length.
What to seek: Balance between 2-5 characters for most languages. Arabic/morphologically-rich languages may benefit from slightly longer tokens.
Unknown Token Rate (OOV Rate)
Definition: Percentage of tokens that map to the unknown/UNK token, indicating words the tokenizer cannot represent.
Intuition: Lower OOV means better vocabulary coverage. High OOV indicates the tokenizer encounters many unseen character sequences.
What to seek: Below 1% is excellent; below 5% is acceptable. BPE tokenizers typically achieve very low OOV due to subword fallback.
N-gram Model Metrics
Perplexity
Definition: Measures how "surprised" the model is by test data. Mathematically: 2^(cross-entropy). Lower values indicate better prediction.
Intuition: If perplexity is 100, the model is as uncertain as if choosing uniformly among 100 options at each step. A perplexity of 10 means effectively choosing among 10 equally likely options.
What to seek: Lower is better. Perplexity decreases with larger n-grams (more context). Values vary widely by language and corpus size.
Entropy
Definition: Average information content (in bits) needed to encode the next token given the context. Related to perplexity: perplexity = 2^entropy.
Intuition: High entropy means high uncertainty/randomness; low entropy means predictable patterns. Natural language typically has entropy between 1-4 bits per character.
What to seek: Lower entropy indicates more predictable text patterns. Entropy should decrease as n-gram size increases.
Coverage (Top-K)
Definition: Percentage of corpus occurrences explained by the top K most frequent n-grams.
Intuition: High coverage with few patterns indicates repetitive/formulaic text; low coverage suggests diverse vocabulary usage.
What to seek: Depends on use case. For language modeling, moderate coverage (40-60% with top-1000) is typical for natural text.
Markov Chain Metrics
Average Entropy
Definition: Mean entropy across all contexts, measuring average uncertainty in next-word prediction.
Intuition: Lower entropy means the model is more confident about what comes next. Context-1 has high entropy (many possible next words); Context-4 has low entropy (few likely continuations).
What to seek: Decreasing entropy with larger context sizes. Very low entropy (<0.1) indicates highly deterministic transitions.
Branching Factor
Definition: Average number of unique next tokens observed for each context.
Intuition: High branching = many possible continuations (flexible but uncertain); low branching = few options (predictable but potentially repetitive).
What to seek: Branching factor should decrease with context size. Values near 1.0 indicate nearly deterministic chains.
Predictability
Definition: Derived metric: (1 - normalized_entropy) × 100%. Indicates how deterministic the model's predictions are.
Intuition: 100% predictability means the next word is always certain; 0% means completely random. Real text falls between these extremes.
What to seek: Higher predictability for text generation quality, but too high (>98%) may produce repetitive output.
Vocabulary & Zipf's Law Metrics
Zipf's Coefficient
Definition: The slope of the log-log plot of word frequency vs. rank. Zipf's law predicts this should be approximately -1.
Intuition: A coefficient near -1 indicates the corpus follows natural language patterns where a few words are very common and most words are rare.
What to seek: Values between -0.8 and -1.2 indicate healthy natural language distribution. Deviations may suggest domain-specific or artificial text.
R² (Coefficient of Determination)
Definition: Measures how well the linear fit explains the frequency-rank relationship. Ranges from 0 to 1.
Intuition: R² near 1.0 means the data closely follows Zipf's law; lower values indicate deviation from expected word frequency patterns.
What to seek: R² > 0.95 is excellent; > 0.99 indicates near-perfect Zipf adherence typical of large natural corpora.
Vocabulary Coverage
Definition: Cumulative percentage of corpus tokens accounted for by the top N words.
Intuition: Shows how concentrated word usage is. If top-100 words cover 50% of text, the corpus relies heavily on common words.
What to seek: Top-100 covering 30-50% is typical. Higher coverage indicates more repetitive text; lower suggests richer vocabulary.
Word Embedding Metrics
Isotropy
Definition: Measures how uniformly distributed vectors are in the embedding space. Computed as the ratio of minimum to maximum singular values.
Intuition: High isotropy (near 1.0) means vectors spread evenly in all directions; low isotropy means vectors cluster in certain directions, reducing expressiveness.
What to seek: Higher isotropy generally indicates better-quality embeddings. Values > 0.1 are reasonable; > 0.3 is good. Lower-dimensional embeddings tend to have higher isotropy.
Average Norm
Definition: Mean magnitude (L2 norm) of word vectors in the embedding space.
Intuition: Indicates the typical "length" of vectors. Consistent norms suggest stable training; high variance may indicate some words are undertrained.
What to seek: Relatively consistent norms across models. The absolute value matters less than consistency (low std deviation).
Cosine Similarity
Definition: Measures angular similarity between vectors, ranging from -1 (opposite) to 1 (identical direction).
Intuition: Words with similar meanings should have high cosine similarity. This is the standard metric for semantic relatedness in embeddings.
What to seek: Semantically related words should score > 0.5; unrelated words should be near 0. Synonyms often score > 0.7.
t-SNE Visualization
Definition: t-Distributed Stochastic Neighbor Embedding - a dimensionality reduction technique that preserves local structure for visualization.
Intuition: Clusters in t-SNE plots indicate groups of semantically related words. Spread indicates vocabulary diversity; tight clusters suggest semantic coherence.
What to seek: Meaningful clusters (e.g., numbers together, verbs together). Avoid over-interpreting distances - t-SNE preserves local, not global, structure.
General Interpretation Guidelines
- Compare within model families: Metrics are most meaningful when comparing models of the same type (e.g., 8k vs 64k tokenizer).
- Consider trade-offs: Better performance on one metric often comes at the cost of another (e.g., compression vs. OOV rate).
- Context matters: Optimal values depend on downstream tasks. Text generation may prioritize different metrics than classification.
- Corpus influence: All metrics are influenced by corpus characteristics. Wikipedia text differs from social media or literature.
- Language-specific patterns: Morphologically rich languages (like Arabic) may show different optimal ranges than analytic languages.
Visualizations Index
| Visualization | Description |
|---|---|
| Tokenizer Compression | Compression ratios by vocabulary size |
| Tokenizer Fertility | Average token length by vocabulary |
| Tokenizer OOV | Unknown token rates |
| Tokenizer Total Tokens | Total tokens by vocabulary |
| N-gram Perplexity | Perplexity by n-gram size |
| N-gram Entropy | Entropy by n-gram size |
| N-gram Coverage | Top pattern coverage |
| N-gram Unique | Unique n-gram counts |
| Markov Entropy | Entropy by context size |
| Markov Branching | Branching factor by context |
| Markov Contexts | Unique context counts |
| Zipf's Law | Frequency-rank distribution with fit |
| Vocab Frequency | Word frequency distribution |
| Top 20 Words | Most frequent words |
| Vocab Coverage | Cumulative coverage curve |
| Embedding Isotropy | Vector space uniformity |
| Embedding Norms | Vector magnitude distribution |
| Embedding Similarity | Word similarity heatmap |
| Nearest Neighbors | Similar words for key terms |
| t-SNE Words | 2D word embedding visualization |
| t-SNE Sentences | 2D sentence embedding visualization |
| Position Encoding | Encoding method comparison |
| Model Sizes | Storage requirements |
| Performance Dashboard | Comprehensive performance overview |
About This Project
Data Source
Models trained on wikipedia-monthly - a monthly snapshot of Wikipedia articles across 300+ languages.
Project
A project by Wikilangs - Open-source NLP models for every Wikipedia language.
Maintainer
Citation
If you use these models in your research, please cite:
@misc{wikilangs2025,
author = {Kamali, Omar},
title = {Wikilangs: Open NLP Models for Wikipedia Languages},
year = {2025},
doi = {10.5281/zenodo.18073153},
publisher = {Zenodo},
url = {https://huggingface.co/wikilangs}
institution = {Omneity Labs}
}
License
MIT License - Free for academic and commercial use.
Links
- 🌐 Website: wikilangs.org
- 🤗 Models: huggingface.co/wikilangs
- 📊 Data: wikipedia-monthly
- 👤 Author: Omar Kamali
- 🤝 Sponsor: Featherless AI
Generated by Wikilangs Models Pipeline
Report Date: 2026-01-11 01:22:30



















