Editing Trigram (section)

==Frequency==
[[Context (language use)|Context]] is very important, varying analysis rankings and percentages are easily derived by drawing from different sample sizes, different authors; or different document types: poetry, science-fiction, technology documentation; and writing levels: stories for children versus adults, military orders, and recipes.

Typical [[cryptanalytic]] [[frequency analysis]] finds that the 16 most common character-level trigrams in English are:<ref name="lewand">{{cite book |last= Lewand |first= Robert |title= Cryptological Mathematics |publisher= [[The Mathematical Association of America]] |year= 2000 |page= 37 |url= {{google books |id= dx8zM-VeKI8C |page= 37 |text= Most Common Trigraphs in the English Language |plainurl= yes}} |isbn= 978-0-88385-719-9}}</ref><ref>{{cite web |url= http://pages.central.edu/emp/LintonT/classes/spring01/cryptography/letterfreq.html |title= Relative Frequencies of Letters in General English Plain text |website= [[Central College (Iowa)|Central College]] |first= Tom |last= Linton |url-status= dead |archive-date= January 22, 2007 |archive-url= https://web.archive.org/web/20070122235914/http://pages.central.edu/emp/LintonT/classes/spring01/cryptography/letterfreq.html |date= 2001 |series= Cryptography |edition= Spring }}</ref>

{|class="wikitable sortable"
|-
!Rank<ref name="lewand" /> !!Trigram !!Frequency<ref>{{cite web |url= http://practicalcryptography.com/cryptanalysis/letter-frequencies-various-languages/english-letter-frequencies/ |title= English Letter Frequencies |website= Practical Cryptography }}</ref><br /><small>(Different source)</small>
|-
|1||'''the'''||1.81%
|-
|2||'''and'''||0.73%
|-
|3||'''tha'''||0.33%
|-
|4||'''ent'''||0.42%
|-
|5||'''ing'''||0.72%
|-
|6||'''ion'''||0.42%
|-
|7||'''tio'''||0.31%
|-
|8||'''for'''||0.34%
|-
|9||'''nde'''||
|-
|10||'''has'''||
|-
|11||'''nce'''||
|-
|12||'''edt'''||
|-
|13||'''tis'''||
|-
|14||'''oft'''||0.22%
|-
|15||'''sth'''||0.21%
|-
|16||'''men'''||
|}

Because encrypted messages sent by [[telegraph]] often omit punctuation and spaces, cryptographic frequency analysis of such messages includes trigrams that straddle word boundaries. This causes trigrams such as "edt" to occur frequently, even though it may never occur in any one word of those messages.<ref>{{cite web |url= https://fuelonline.com/voice-search-seo-voice-seo/ |title= Voice Search SEO |website= Fuelonline }}</ref>