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Rohit Ghumare dda194f840 fix(quiz): correct answer is always in the same position (slot B) (#381)
Every "Test Your Understanding" quiz placed the correct answer in option B.
Across the 2026 questions in 338 quiz files the correct answer sat at index 1
in 61.5% of cases (uniform would be ~25%), and 107 files had every answer at B,
making the quizzes guessable without reading them.

scripts/debias_quizzes.py rewrites each question's option order with a
deterministic, content-seeded permutation and updates the correct index to
follow the moved answer. It is idempotent: options are canonicalised to a sorted
base before permuting, so re-running produces byte-identical output. Questions
whose options reference each other by position ("all of the above", "both A and
B") are left untouched. The correct-answer value, the option set, and every
explanation are preserved exactly; only order and the index change.

Result: A 23.8% / B 26.3% / C 23.5% / D 26.4%.

The script doubles as a CI guard: `--check` exits non-zero if any quiz is not
de-biased, wired into the curriculum workflow so new lessons cannot regress.

Fixes #368
2026-08-01 14:24:15 +01:00

103 lines
3.6 KiB
JSON

{
"lesson": "01-text-processing",
"title": "Text Processing — Tokenization, Stemming, Lemmatization",
"questions": [
{
"stage": "pre",
"question": "Why does a language model need preprocessing before training?",
"options": [
"Models read strings directly",
"Preprocessing improves GPU utilization",
"Models consume discrete integer tokens, not raw text",
"Preprocessing is required only for languages without whitespace"
],
"correct": 2,
"explanation": "Models operate on integer token IDs; preprocessing bridges continuous language to discrete inputs."
},
{
"stage": "pre",
"question": "Which preprocessing operation is rule-based suffix stripping?",
"options": [
"POS tagging",
"Stemming",
"Lemmatization",
"Tokenization"
],
"correct": 1,
"explanation": "Stemming chops suffixes with rules; it is fast but can be wrong."
},
{
"stage": "check",
"question": "What does the Porter stemmer step 1a return for the word 'ponies'?",
"options": [
"poni",
"ponies",
"pony",
"ponie"
],
"correct": 0,
"explanation": "The 'ies' rule replaces the suffix with 'i', producing 'poni'; step 1b in real Porter cleans it up."
},
{
"stage": "check",
"question": "Why does lemmatization usually need a POS tag?",
"options": [
"Unicode handling",
"Grammatical context disambiguates forms like 'better' (ADJ) versus 'better' (VERB)",
"To reduce memory usage",
"Speed"
],
"correct": 1,
"explanation": "Lemmas depend on grammatical role; without the tag the lookup is ambiguous."
},
{
"stage": "check",
"question": "When translating NLTK Penn Treebank POS tags to WordNet tags, what does a tag starting with 'V' map to?",
"options": [
"'r' (adverb)",
"'a' (adjective)",
"'v' (verb)",
"'n' (noun)"
],
"correct": 2,
"explanation": "Verb-prefixed Penn Treebank tags map to WordNet 'v'."
},
{
"stage": "post",
"question": "What is 'training/inference mismatch' in NLP preprocessing?",
"options": [
"A GPU memory issue",
"Training and serving apply different preprocessing, so the model sees an unfamiliar distribution at inference",
"Mixing tokenizer libraries within a notebook",
"Different batch sizes between train and test"
],
"correct": 1,
"explanation": "Different preprocessing at training vs inference is the most common production NLP failure."
},
{
"stage": "post",
"question": "Which tool would you reach for in a transformer pipeline instead of classical preprocessing?",
"options": [
"NLTK word_tokenize",
"The model's own tokenizer (e.g. via tokenizers / transformers)",
"spaCy en_core_web_sm",
"A regex tokenizer"
],
"correct": 1,
"explanation": "Transformer models ship a paired tokenizer; classical preprocessing is bypassed."
},
{
"stage": "post",
"question": "Why pin NLTK and spaCy versions in requirements?",
"options": [
"Newer versions are slower",
"Older versions support more languages",
"Tokenizer and lemmatizer behavior shifts between minor releases, silently changing training distribution",
"License compatibility"
],
"correct": 2,
"explanation": "Library upgrades can change tokenization output, drifting from the training distribution."
}
]
}