# Natural language processing quiz questions with answers, NLP true false interview questions, NLP quiz questions for competitive exams

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__NLP TRUE/FALSE Quiz Questions - SET 04__

__NLP TRUE/FALSE Quiz Questions - SET 04__

1. While computing
the language model probabilities in log format, we multiply the log
probabilities to derive the probability of the given model.

(a)
TRUE (b)
FALSE

**View Answer**Answer:
(b) FALSEAdding in log space is same as multiplying in linear space.
Later we can find the exp of added log probabilities to get back the
probability of the given model as follows;p1 * p2 * p3 = exp(log p1 + log p2 + log p3)Example:Let us suppose, p1 = 0.025, p2 = 0.033, and p2 = 0.05.p1 * p2 * p3 = 0.025 * 0.033 * 0.05 = 0.00004125 which is very
small.Instead of the above calculation, we can perform the
following;Exp(log p1 + log p2 + log p3) = exp(-1.6 + (-1.48) + (-1.3)) =
exp(-4.38) = 10^{-4.38} = 0.00004169. |

2. To measure the
quality of a language model, we use the metric intrinsic evaluation on the
training data set.

(a)
TRUE (b)
FALSE

**View Answer**Answer:
(b) FALSEIntrinsic evaluation is a metric to measure the quality of a
language model independent of any application. And for this, we need test
data set.Also, we do not need external applications to evaluate the
performance as in the case of extrinsic evaluation. |

3. Since the
language model is meant to assign non-zero probability to unseen strings of
words, a mandatory desirable property is Smoothing.

(a)
TRUE (b)
FALSE

**View Answer**Answer:
(a) TRUEUnknown words (out-of-vocabulary words) usually cause the
problem in a language model. The probability value of unknown words will be
zero, and due to multiplication of probabilities, the entire probability will
become zero. To avoid zero probabilities, we need to do smoothing. Some smoothing techniques are Laplace smoothing, Add-k
smoothing, Interpolated Kneser-Ney smoothing etc. |

4. The production
rules of Context Free Grammar (CFG) should be in Chomsky Normal Form (CNF).

(a)
TRUE (b)
FALSE

**View Answer**Answer:
(b) FALSEThe grammar of CFG is need not be in Chomsky normal form.Production rules of CFG can have a combination of non-terminal
and terminal symbols on the right hand side. In CNF, a rule can have only one
terminal on its RHS (no other symbols) or two non-terminals on it RHS. |

5. In backoff
smoothing technique, we use the bigrams if the evidence for trigram is
insufficient.

(a)
TRUE (b)
FALSE

**View Answer**Answer:
(a) TRUEIn backoff, we use the trigram if the evidence is sufficient,
otherwise we use the bigram, otherwise the unigram. In other words, we only
“back off” to a lower-order n-gram if we have zero evidence for a
higher-order interpolation n-gram.It is a non-linear method. The estimate for an n-gram is
allowed to back off through progressively shorter histories. The most
detailed model that can provide sufficiently reliable information about the
current context is used. |

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__Related links:__

- Go to Natural Langugage Processing home page

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