A formula for the test set perplexity ( Lee 1989 ) is :13
automatic speech recognition the development of the sphinx system appendix i
K F Lee
The grammar could parse 100 % of the training sentences and 84 % of the test sentences . A formula for the test set perplexity ( Lee 1989 ) is :13 where the wi are the sequence of all words in all sentences , N is the total number of words , including an `` end '' word after each sentence , and P ( w , I w , _ 1 , ... wi ) is the probability of the ith word given all preceding words .14 If all words are assumed equally likely , then P ( w , I w , _ 1 , ... w1 ) can be determined by counting all the words that could follow each word in the sentence , along all workable partial theories .
A formula for the test set perplexity ( @@CITATION ) is :13