Letter frequency is the number of times letters of the alphabet appear on average in written language. Letter frequency analysis dates back to the Arab mathematician Al-Kindi (c. 801–873 AD), who formally developed the method to break ciphers. Letter frequency analysis gained importance in Europe with the development of movable type in 1450 AD, where one must estimate the amount of type required for each letterform. Linguists use letter frequency analysis as a rudimentary technique for language identification, where it is particularly effective as an indication of whether an unknown writing system is alphabetic, syllabic, or ideographic.
The use of letter frequencies and frequency analysis plays a fundamental role in cryptograms and several word puzzle games, including hangman, Scrabble, Wordle[2] and the television game show Wheel of Fortune. One of the earliest descriptions in classical literature of applying the knowledge of English letter frequency to solving a cryptogram is found in Edgar Allan Poe's famous story "The Gold-Bug", where the method is successfully applied to decipher a message giving the location of a treasure hidden by Captain Kidd.[3][citation needed]
Herbert S. Zim, in his classic introductory cryptography text Codes and Secret Writing, gives the English letter frequency sequence as "ETAON RISHD LFCMU GYPWB VKJXZQ", the most common letter pairs as "TH HE AN RE ER IN ON AT ND ST ES EN OF TE ED OR TI HI AS TO", and the most common doubled letters as "LL EE SS OO TT FF RR NN PP CC".[4] Different ways of counting can produce somewhat different orders.
Letter frequencies also have a strong effect on the design of some keyboard layouts. The most frequent letters are placed on the home row of the Blickensderfer typewriter, the Dvorak keyboard layout, Colemak and other optimized layouts.
^Mička, Pavel. "Letter frequency (English)". Algoritmy.net. Archived from the original on 4 March 2021. Retrieved 14 June 2022. Source is Leland, Robert. Cryptological mathematics. [s.l.] : The Mathematical Association of America, 2000. 199 p. ISBN 0-88385-719-7
^Guinness, Harry. "The Best Starting Words to Win at Wordle". Wired. ISSN 1059-1028. Retrieved 2022-02-12.
^Poe, Edgar Allan. "The works of Edgar Allan Poe in five volumes". Project Gutenberg.
^Zim, Herbert Spencer (1961). Codes & Secret Writing: Authorized Abridgement. Scholastic Book Services. OCLC 317853773.
Letterfrequency is the number of times letters of the alphabet appear on average in written language. Letterfrequency analysis dates back to the Arab...
used to express a guess that ciphertext letter X represents the plaintext letter t. Eve could use frequency analysis to help solve the message along...
PMID 31287075. Retrieved 16 December 2023. Gelb & Whiting 1998, p. 45 "Letterfrequency (English)". Archived from the original on 4 March 2021. Retrieved 3...
The letterfrequency effect is an effect of letterfrequency, according to which the frequency with which the letter is encountered influences the recognition...
frequency of letters in text has often been studied for use in cryptanalysis, and frequency analysis in particular. No language has an exact letter frequency...
the mid front unrounded vowel. 'E' is the most common (or highest-frequency) letter in the English language alphabet and several other European languages...
ISBN 3-87439-260-0. "English LetterFrequency". Archived from the original on 2014-05-23. Retrieved 2014-05-21. "LetterFrequencies in the English Language"...
term frequency is defined as the number of cycles or repetitions per unit of time. The conventional symbol for frequency is f or ν (the Greek letter nu)...
of the English Language, Unabridged (1993); "en," op. cit. "English LetterFrequency". Cook, Richard; Everson, Michael (2001-09-20). "L2/01-347: Proposal...
The frequency illusion (also known as the Baader–Meinhof phenomenon) is a cognitive bias in which a person notices a specific concept, word, or product...
) Letter beacons have been referred to as: SLB, or "Single Letter Beacons" SLHFB, or "Single Letter High Frequency Beacons" SLHFM, or "Single Letter High...
symbol). X is the third least frequently used letter in English (after ⟨q⟩ and ⟨z⟩), with a frequency of about 0.15% in words. In Latin, ⟨x⟩ stood for...
frequencies of 30 GHz and above are designated millimeter wave. More detailed band designations are given by the standard IEEE letter- band frequency...
of the ISO basic Latin alphabet plus ⟨ñ⟩. The letter ⟨ç⟩ is officially not considered a separate letter, but a variant of ⟨c⟩. This is the whole list...
containing a string of repeated bigrams, such as logogogue. The frequency of the most common letter bigrams in a large English corpus is: th 3.56% of 1.17% io...
by their frequency. The letters on type-casting machine keyboards (such as Linotype and Intertype) were arranged by descending letterfrequency to speed...
intended for the English language. For other European languages, letterfrequencies, letter sequences, and bigrams differ from those of English. Also, many...
the electromagnetic spectrum with frequencies from 3 Hz to 3,000 GHz (3 THz). Electromagnetic waves in this frequency range, called radio waves, are widely...
increase the difficulty of frequency analysis attacks on substitution ciphers was to disguise plaintext letterfrequencies by homophony. In these ciphers...
within other words. It is the least frequently used letter in written English, with a frequency of about 0.08% in words. ⟨z⟩ is more common in the Oxford...
control and use of ciphers and codes. See results of analysis of "LetterFrequencies in the English Language". Context is very important, varying analysis...
Z, the letter K is not used very frequently in English. It is the fifth least frequently used letter in the English language, with a frequency in words...
emblazoned prevalent Excluding leading letters "s m i t h y c o d e", the letterfrequencies are as follows: a – 4 e – 3 g, m, p, q, s, t – 2 c, d, f, i, j, k...
Global Information