Day 1 · Monday · Problem set
Prediction claims, baselines, and evaluation
Choose the best answer. Use the stated unit, prediction moment, denominator, and intended decision. No answer requires information outside this booklet.
Questions 1–3
One row is one parcel scored at acceptance. In 500 audit parcels, 50 arrived more than 24 hours late. A fixed rule flags 40 parcels; 30 flagged parcels were late. The review desk has exactly 40 places.
- Precision of the review queue
What is the rule's precision?
\(30/40=75\%\)
\(30/50=60\%\)
\(40/500=8\%\)
\(50/500=10\%\)
- Recall of late parcels
What is the rule's recall?
\(20/50=40\%\)
\(30/40=75\%\)
\(30/50=60\%\)
\(450/500=90\%\)
- A capacity-matched baseline
Randomly selecting 40 of the 500 audit parcels would contain an expected \(40\times 50/500=4\) late parcels. What follows?
The rule's queue prioritises late parcels much better than random selection on this audit
The rule prevents exactly 26 late deliveries
Accuracy must be 96% because 40 records were flagged
The rule is ready for automatic rerouting without a cost or intervention study
Questions 4–6
One row is one enrolled student before term begins. The target is whether the student experiences a defined academic difficulty during the first six weeks. The score may prioritise an invitation to voluntary support; it may not restrict enrolment or impose a penalty.
- Information at the stated prediction moment
Which variable is invalid for the before-term score?
Prior completed course results
Programme and study mode recorded before term
A support appointment completed in week three
A declared support preference recorded before term
- Target and decision are different
The score predicts academic difficulty accurately. What does that fact alone not establish?
Whether the difficulty outcome can be defined
Whether a voluntary support invitation improves outcomes
Whether one row represents one student
Whether earlier course results were recorded
- A responsible use
Which proposed use stays closest to the stated design?
Automatically remove high-scoring students from the programme
Offer a reviewable, voluntary invitation and monitor who is missed or burdened
Publish individual scores to classmates
Treat the score as proof that a student will struggle
Questions 7–9
The classifier will be used in 2027 on documents from organisations absent from development. Old documents run through 2025; later documents from new organisations are available for evaluation.
- Evaluation matched to deployment
Which test best represents the stated 2027 use?
Random rows from old documents, with the same organisations in training and testing
Training performance after model selection
Later documents from organisations kept entirely out of development
Only the easiest documents from the new organisations
- A risk that remains
Even with later documents from unseen organisations, what uncertainty remains?
Whether conditions in 2027 differ from the evaluation period
Whether the training rows have labels
Whether the classifier has an output
Whether unseen organisations are absent from development
- Using an audit twice
The team studies errors on the final evaluation, changes the rule, and reports the revised score on the same rows. Which statement is correct?
The rows now informed development, so fresh untouched cases are needed for a final check
The revised score remains fully independent because no new feature was added
The audit becomes larger after the revision
A higher revised score proves performance in 2027
Questions 10–12
One row is one BIS speech record. The system reads only the supplied public
description and either returns a role explicitly supported by a phrase or
ABSTAIN.
- Coverage and selective accuracy
A system answers 95 of 100 records and is correct on 93 answered records. Which pair is correct?
Coverage \(93\%\); selective accuracy \(95\%\)
Coverage \(95\%\); selective accuracy \(93/95\)
Coverage \(100\%\); selective accuracy \(93\%\)
Coverage \(95/93\); selective accuracy \(95\%\)
- A silent description
The description gives no explicit role phrase. What output follows from the task definition?
Infer the most likely role from the person's name
Search an outside biography
Return
ABSTAINand route the record for review if an answer is requiredUse the institution's most common role
- Do label frequencies describe the institution?
The extractor assigns
SENIOR_STAFFmore often in descriptions from one institution. Which conclusion is supported?The institution promotes more staff into senior roles
The observed descriptions contain the extracted phrase more often; promotion practices were not measured
Senior staff cause more speeches to be published
The classifier has measured institutional fairness