bigram是什么？

昨天看gensim的LDA Model文档的时候， 看到这样一段：

We find bigrams in the documents. Bigrams are sets of two adjacent words. Using bigrams we can get phrases like “machine_learning” in our output (spaces are replaced with underscores); without bigrams we would only get “machine” and “learning”.

Note that in the code below, we find bigrams and then add them to the original data, because we would like to keep the words “machine” and “learning” as well as the bigram “machine_learning”.

bigram是指两个词组成的词组吗

unigram 一元分词，把句子分成一个一个的词
bigram 二元分词，把句子从头到尾每两个字组成一个词语
trigram 三元分词，把句子从头到尾每三个字组成一个词语.
n-gram models就是n元语言模型