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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

79 lines
2.5 KiB
JSON

{
"lesson": "08-inference-metrics-goodput",
"title": "Inference Metrics — TTFT, TPOT, ITL, Goodput, P99",
"questions": [
{
"stage": "pre",
"question": "Which components dominate TTFT (time to first token)?",
"options": [
"Disk I/O for weights",
"Queue time, network request time, and prefill time",
"Tokenizer GIL overhead",
"Decode-only forward time"
],
"correct": 1,
"explanation": ""
},
{
"stage": "check",
"question": "Which metric does the lesson call the one that actually matters for product?",
"options": [
"Goodput — fraction of requests meeting every SLO constraint simultaneously",
"Aggregate throughput in tokens per second",
"Mean ITL",
"GPU duty cycle"
],
"correct": 0,
"explanation": ""
},
{
"stage": "check",
"question": "Why is mean the wrong statistic to report for LLM latency?",
"options": [
"LLM latency distributions are right-skewed; users routinely hit P99 outliers that mean hides",
"Mean is never computable on streaming responses",
"Mean only works for prefill, not decode",
"Mean is not supported by GenAI-Perf"
],
"correct": 0,
"explanation": ""
},
{
"stage": "check",
"question": "Why do GenAI-Perf and LLMPerf disagree on TPOT for the same run?",
"options": [
"They sample different requests",
"GenAI-Perf only runs on Blackwell",
"LLMPerf uses microseconds and GenAI-Perf uses milliseconds",
"GenAI-Perf excludes TTFT from the ITL calculation; LLMPerf includes it, so tool choice changes the number"
],
"correct": 3,
"explanation": ""
},
{
"stage": "post",
"question": "For long-output requests (>500 tokens), which metric dominates end-to-end latency?",
"options": [
"Network response time",
"TPOT times output length",
"TTFT",
"Cold-start time"
],
"correct": 1,
"explanation": ""
},
{
"stage": "post",
"question": "Which set best captures the lesson's reasonable consumer-facing SLO for a 70B chat model in 2026?",
"options": [
"P50 only, no percentiles above",
"TTFT P99 800 ms, TPOT P99 25 ms, E2E P99 3 s for <300-token outputs, goodput >= 99%",
"TTFT P99 8s, TPOT P99 200ms, goodput 50%",
"Mean TTFT 10 ms, mean TPOT 1 ms"
],
"correct": 1,
"explanation": ""
}
]
}