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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
4.0 KiB
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{
"lesson": "11-machine-translation",
"title": "Machine Translation",
"questions": [
{
"stage": "pre",
"question": "What does BLEU measure?",
"options": [
"N-gram precision (typically 1-4) between hypothesis and reference, with a brevity penalty",
"Embedding cosine similarity",
"Language identification accuracy",
"Character-level F-score"
],
"correct": 0,
"explanation": "BLEU is the geometric mean of 1-4-gram precision against references, plus a brevity penalty."
},
{
"stage": "pre",
"question": "Why use sacrebleu instead of rolling your own BLEU?",
"options": [
"It runs on GPU",
"It is more accurate",
"It normalizes tokenization so scores are comparable across papers and runs",
"It supports streaming"
],
"correct": 2,
"explanation": "sacrebleu freezes tokenization, removing a common source of incomparable BLEU numbers."
},
{
"stage": "check",
"question": "Which NLLB-specific setting controls the target language during decoding?",
"options": [
"src_lang",
"forced_bos_token_id set to the target language code's token id",
"num_beams",
"length_penalty"
],
"correct": 1,
"explanation": "NLLB forces the first decoded token to a target-language code via forced_bos_token_id."
},
{
"stage": "check",
"question": "Which metric family is the 2026 default for production MT quality where labeled data exists?",
"options": [
"Token edit distance",
"Latency",
"BLEU alone",
"Learned metrics such as COMET (and BERTScore/BLEURT) trained on human judgment"
],
"correct": 3,
"explanation": "Learned metrics like COMET correlate more strongly with human judgment than BLEU/chrF alone."
},
{
"stage": "check",
"question": "When does chrF tend to be more informative than BLEU?",
"options": [
"For morphologically rich languages where character-level matches catch inflectional variants BLEU misses",
"When using beam search",
"On very short sentences",
"Whenever a reference exists"
],
"correct": 0,
"explanation": "Character F-score captures partial morphological matches that word-level BLEU undercounts."
},
{
"stage": "post",
"question": "What is off-target generation in multilingual MT?",
"options": [
"Output that drops named entities",
"The model decodes into the wrong target language (e.g. NLLB outputting Spanish when French was requested)",
"Output that is too short",
"Output that misses punctuation"
],
"correct": 1,
"explanation": "Off-target generation is common on rare language pairs; a post-translation language-ID check catches it."
},
{
"stage": "post",
"question": "Why does fine-tuning on a few thousand high-quality domain pairs often beat much larger noisy web data?",
"options": [
"Quality and domain match dominate volume; noisy parallel data introduces drift and hallucination",
"Smaller datasets train faster",
"Web data is illegal to use",
"Larger data overflows GPU memory"
],
"correct": 0,
"explanation": "Clean domain-aligned pairs are the largest production lever; noisy data degrades adaptation."
},
{
"stage": "post",
"question": "When is an LLM (e.g. GPT-4) likely to outperform a specialized MT model in 2026?",
"options": [
"Latency-critical browser translation",
"Idiomatic content, long context, stylistic adaptation via prompting, or content requiring tone control",
"Highest throughput batch translation",
"Small-language pairs with millions of parallel sentences"
],
"correct": 1,
"explanation": "LLMs win on idiomatic, long-context, or style-controlled translation; specialized MT wins on throughput and latency."
}
]
}