Google Ngram Viewer

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The Google Ngram Viewer is a phrase-usage graphing tool which charts the yearly count of selected n-grams (letter combinations),[n] words, or phrases,[1][2] as found in over 5.2 million books digitized by Google Inc (up to 2008).[3][4] The words or phrases (or ngrams) are matched by case-sensitive spelling, comparing exact uppercase letters,[2] and plotted on the graph if found in 40 or more books.[5] The Ngram tool was released in mid-December 2010.[1][3]

The word-search database was created by Google Labs, based originally on 5.2 million books, published between 1500 and 2008, containing 500 billion words[6] in American English, British English, French, German, Spanish, Russian, or Chinese.[1] Italian words are counted by their use in other languages. A user of the Ngram tool has the option to select among the source languages for the word-search operations.[7]


Operation and restrictions

The Ngram Viewer returns a plotted line chart within seconds of listing entries and pressing the Enter key or the "Search" button on the screen. The entries are separated by commas, to indicate each separate word or phrase to find.[5] As an adjustment for more books having been published during some years, the data is normalized, as a relative level, by the number of books published in each year.[5]

The database was created from over 5 million books published up to 2008, and so, as of May 2012, no data will match beyond the year 2008. Due to limitations on the size of the Ngram database, only matches found in over 40 books are indexed in the database; otherwise, not all known combinations could have been stored.[5]

Typically, entries cannot end with punctuation, although a separate full stop, or period, can be searched.[5] Also, an ending question mark (as in "Why?") will cause a 2nd search for the question mark separately.[5]

Omitting the periods in abbreviations will allow a form of matching, such as using "R M S" to search for "R.M.S." versus "RMS".

See also


[n] - An "ngram" is a sequence of letters of any length, which could be a word, a misspelling, a phrase or gibberish.[6]
  1. ^ a b c "Google Ngram Database Tracks Popularity Of 500 Billion Words" Huffington Post, 17 December 2010, webpage: HP8150.
  2. ^ a b "Google Ngram Viewer - Google Books",, May 2012, webpage: G-Ngrams.
  3. ^ a b "Google's Ngram Viewer: A time machine for wordplay",, 17 December 2010, webpage: CN93.
  4. ^ "A Picture is Worth 500 Billion Words – By Rusty S. Thompson",, 20 September 2011, webpage: HBMag20.
  5. ^ a b c d e f "Google Ngram Viewer - Google Books" (Information),, December 16, 2010, webpage: G-Ngrams-info: notes bigrams and use of quotes for words with apostrophes.
  6. ^ a b "Google Books Ngram Viewer - University at Buffalo Libraries",, 22 August 2011, webpage: Buf497.
  7. ^ "Google NGrams: What We Learned From 5 Million Books",, 25 September 2011, webpage: CLS25.

External links