A certain little-known human language consists of only nouns and verbs. A sentence begins with a noun with probability 75% and with a verb with probability 25%. If a given word in a sentence is a noun, there is a 75% probability that the next word is a verb and a 25% probability that the next word is a noun. If a given word is a verb, there is a 75% probability that the next word in the sentence is a noun and a 25% probability that is a verb. We can model this language using a Markov chain with two states: noun and verb. Question 1: There are only four words in the language: awk, yacc, grep, and perl. Each of these words can be either a noun or a verb. Of all noun occurrences, 10% are the word awk, 20% are the word yacc, 40% are the word grep, and 30% are the word perl. Of all verb occurrences, 20% are the word awk, 30% are the word yacc, 45% are the word grep, and 5% are the word perl. Using the Markov model described above and the Variable Elimination algorithm, find the probability that the fourth word of the following sentence is a noun: Perl yacc awk awk. Remember that you can express this sentence with the following Bayes' net: So in other words, the question is what is P(Q4 = noun | O1 = perl, O2 = yacc, O3 = awk, O4 = awk)? a) around 20.65% b) around 67.55% c) around 34.23% d) around 60.96%
A certain little-known human language consists of only nouns and verbs. A sentence begins with a noun with probability 75% and with a verb with probability 25%. If a given word in a sentence is a noun, there is a 75% probability that the next word is a verb and a 25% probability that the next word is a noun. If a given word is a verb, there is a 75% probability that the next word in the sentence is a noun and a 25% probability that is a verb.
We can model this language using a Markov chain with two states: noun and verb.
Question 1:
There are only four words in the language: awk, yacc, grep, and perl. Each of these words can be either a noun or a verb. Of all noun occurrences, 10% are the word awk, 20% are the word yacc, 40% are the word grep, and 30% are the word perl. Of all verb occurrences, 20% are the word awk, 30% are the word yacc, 45% are the word grep, and 5% are the word perl.
Using the Markov model described above and the Variable Elimination algorithm, find the probability that the fourth word of the following sentence is a noun: Perl yacc awk awk.
Remember that you can express this sentence with the following Bayes' net:
So in other words, the question is what is P(Q4 = noun | O1 = perl, O2 = yacc, O3 = awk, O4 = awk)?
a) around 20.65%
b) around 67.55%
c) around 34.23%
d) around 60.96%
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