Bigram is a term used to describe a sequence of two items, usually words. For example, the phrase “I am” would be considered a bigram. Bigrams can be used to disambiguate meaning, since the order of words often changes the meaning of a sentence. For example, consider the bigrams “I am” and “am I”. The first suggests that the speaker is introducing themselves, while the second suggests that the speaker is asking a question.
The bigram is similar to the terms trigram and quadgram, which refer to sequences of three and four items, respectively. However, the term bigram is more commonly used than trigram or quadgram.
Importance of Bigram
While bigram is not as common a term outside of the text analytics industry, it is still an important concept. Bigrams can be used to improve the accuracy of text-based predictions, such as those made by statistical language models. In addition, bigrams can be used to help disambiguate the meaning of a sentence. For example, if a statistical language model predicts that the word “I” is likely to be followed by the word “am”, this prediction can be used to disambiguate the meaning of the sentence “I am”.
Moreover, bigram is also important in the field of cryptography. A bigram cipher is a type of substitution cipher in which each pair of letters is replaced with another pair of letters. The bigram cipher is an example of a polyalphabetic cipher, which is a type of cipher that uses multiple alphabets.
Bigram vs. other terms
Bigram is sometimes confused with the terms bigraph and digraph. However, these terms have different meanings. A bigraph is a graph consisting of two vertices and two edges, while a digraph is a directed graph. Both bigraph and digraph are terms used in mathematics, not in the text analytics industry.
In linguistics, a bigram is simply any two consecutive letters, whether they form words or not. For example, the string “th” is a bigram in the English language, since it appears often in words such as “the,” “this,” and “that.” However, note that the term bigram only applies to letters, and not to numbers or other characters.
In general, bigram can refer to any two-part sequence, whether it be words, letters, numbers, or anything else. The important thing to remember is that the term only applies to two consecutive items, and not to three or more items.