Natural Language Processing · M2 · mocks

Q2 (2 marks)

M2 Mock C · mixed numerical practice

M2 · confirmed 2 + 2 + any two of 3 + 3 + 3 · worked practice

Q2

Each of five words may receive any of three POS tags. How many possible tag sequences exist before applying constraints? (2 marks)

Given

T=5 token positions; K=3 choices at each position.

To find

Total tag sequences.

Formula and why it applies

K^TLaTeX: K^T

Choose one tag independently for each position when counting candidates; multiply the number of options five times.

Solution

Step 1. Expand the power

3^5=3\times3\times3\times3\times3LaTeX: 3^5=3\times3\times3\times3\times3

Step 2. Multiply

3\times3=9,\quad9\times3=27LaTeX: 3\times3=9,\quad9\times3=27
27\times3=81,\quad81\times3=243LaTeX: 27\times3=81,\quad81\times3=243
243 tag sequences.