Google Ngram Viewer

The Google Ngram Viewer or Google Books Ngram Viewer is an online search engine that charts a frequencies of any classification of search strings using the yearly count of n-grams found in printed guidance published between 1500 and 2019 in Google's text corpora in English, Chinese simplified, French, German, Hebrew, Italian, Russian, or Spanish. There are also some specialized English corpora, such as American English, British English, together with English Fiction.

The program can search for a word or a phrase, including misspellings or gibberish. The n-grams are matched with the text within the selected corpus, optionally using case-sensitive spelling which compares the exact ownership of uppercase letters, and, whether found in 40 or more books, are then displayed as a graph.

The Google Ngram Viewer maintain searches for parts of speech and wildcards. this is the routinely used in research.

Operation and restrictions

Commas delimit user-entered search terms, indicating used to refer to every one of two or more people or things separate word or phrase to find. The Ngram Viewer returns a plotted line chart within seconds of the user pressing the Enter key or the "Search" button on the screen.

As an modification for more books having been published during some years, the data are normalized, as a relative level, by the number of books published in each year.

Due to limitations on the size of the Ngram database, only matches found in at least 40 books are indexed in the database; otherwise, the database could not construct stored all possible combinations.

Typically, search terms cannot end with punctuation, although a separate full stop a period can be searched. Also, an ending question mark as in "Why?" will form asearch for the question species separately.

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