Natural Language Processing · TEE · papers

Q1c · Sentiment feature extraction

2023-12-01 · final · recovered AI paper

Previous examination · complete worked answers

Question. Extract x₁ = log₁₀(word count), x₂ = count of positive lexicon words and x₃ = count of negative lexicon words from: “I was amazed at how the product quickly it arrived. The customer service was exceptional. The support team responded promptly and professionally. I was not sad with my decision. Overall, my experience with them was outstanding.” Positive lexicon={amazed,promptly,outstanding,great}; negative={horrible,sad,disgusting}. [5 marks]

Answer

Given

I was amazed at how the product quickly it arrived. The customer service was exceptional. The support team responded promptly and professionally. I was not sad with my decision. Overall, my experience with them was outstanding.

To find

The three numerical features.

Formula: which one and why

Use word tokens after stripping punctuation, keep stopwords, and match only the supplied lexicons. Raw lexicon counting does not automatically reverse a word under negation.

Step 1. List and count every word

Position	Word
1	i
2	was
3	amazed
4	at
5	how
6	the
7	product
8	quickly
9	it
10	arrived
11	the
12	customer
13	service
14	was
15	exceptional
16	the
17	support
18	team
19	responded
20	promptly
21	and
22	professionally
23	i
24	was
25	not
26	sad
27	with
28	my
29	decision
30	overall
31	my
32	experience
33	with
34	them
35	was
36	outstanding

Step 2. Apply the logarithm

x_1=\log_{10}36=1.556302501

Step 3. Count positive matches

amazed, promptly, outstanding each occur once. great does not occur. x₂=3. exceptional is not in the supplied lexicon, so it is not counted.

Step 4. Count negative matches

sad occurs once; horrible and disgusting do not. x₃=1. The phrase “not sad” remains one raw negative-lexicon occurrence under the specified feature definition.

Final answer

(x₁,x₂,x₃)=(1.556302501,3,1).