MS-DS Master of Data science Master of Data Science Natural Language Processing 1

Question 1

Which algorithm is commonly used to segment text into subword units, helping models handle out-of-vocabulary words?

Accepted Answer

Byte Pair Encoding (BPE)

Answer

Byte Pair Encoding iteratively merges the most frequent character pairs to build a subword vocabulary, allowing models to represent rare or unseen words as combinations of known subword tokens.

Question 2

In the transformer architecture, what does the term 'positional encoding' accomplish?

Accepted Answer

It injects information about each token's position in the sequence

Answer

Because transformers process all tokens in parallel without recurrence, positional encodings (sinusoidal or learned vectors) are added to embeddings so the model can distinguish token order.

Question 3

Which evaluation metric computes the geometric mean of precision and recall, and is widely used for NLP classification tasks?

Accepted Answer

F1 score

Answer

The F1 score is the harmonic mean of precision and recall, giving a single balanced measure especially useful when class distributions are uneven.

Question 4

What distinguishes a bidirectional LSTM from a standard (unidirectional) LSTM?

Accepted Answer

It reads the input sequence in both forward and backward directions simultaneously

Answer

A bidirectional LSTM runs two separate LSTMs — one left-to-right and one right-to-left — then concatenates their hidden states, giving each token context from both past and future tokens.

Question 5

In the context of topic modeling, what does Latent Dirichlet Allocation (LDA) assume about documents?

Accepted Answer

Documents are mixtures of topics, and topics are mixtures of words

Answer

LDA is a generative probabilistic model that treats each document as a mixture of latent topics and each topic as a probability distribution over vocabulary words, ignoring word order (bag-of-words assumption).

MS-DS Master of Data science Practice Test

MS-DS Master of Data science Practice Test

MS-DS Master of Data science Master of Data Science Natural Language Processing 1