Advanced Database Management System - Tutorials and Notes: Natural Language Processing MCQ 09

# MCQ in Natural Language Processing, Quiz questions with answers in NLP, Top interview questions in NLP with answers

## Multiple Choice Questions and Answers in NLP Set - 09

1. Consider the following simple bigram language model, where the vocabulary consists of the single word x, and the parameters of the model are;
q(a|*) = 1.0; q(a|a) = 0.4; q(END|a) = 0.6
Which of the following are the probabilities of the string ‘* a a’ with and without END?
a) 1, 0.4
b) 0.4, 0.24
c) 0.4, 0.6
d) 1.4, 1.0

 Answer: (b) 0.4, 0.24 The probability of the given string can be derived by multiplying appropriate state transition probabilities. As per the question, we need to calculate the following; P(“* a a”) = P(a|*) * P(a|a) = 1.0 * 0.4 = 0.4 P(“* a a END”) = P(a|*) * P(a|a) * P(END|a) = 1.0 * 0.4 * 0.6 = 0.24

### 2. Which of the following measurements are used to evaluate the quality of entity recognition?

a) Precision
b) Recall
c) F-measure
d) All of the above

 Answer: (d) All of the above Entity recognition is a task of identifying and classifying the entity mentions like person names, organizations, locations etc. in the text. The quality of entity recognition cane be measures using the measurements precision, recall, and F-measure. Precision is the percentage of entities correctly recognized by the underlying system, and can be measured as follows; Precision = correctly recognized/actual recognized Recall is the percentage of entities recognized by the underlying system out of all correct entities with respect to some gold standard dataset. Recall = correctly recognized/all correct entities F-measure is the harmonic mean of precision and recall

### 3. What is the number of trigrams in a normalized sentence of length n words?

a) n
b) n-1
c) n-2
d) n-3

 Answer: (c) n-2 Trigrams are group of threes words that are written consecutively. Trigrams are extracted by sliding window of size 3 over the given text. Number of trigrams in a document of length n words = n-2 where n>=3.

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