50 minutes. Self-marked against the rubric. 14 marks. In the full course this counts toward the labs and cases share (15% of the course grade). Write your answers in the boxes, then open the model answer and tick each mark you earned honestly. Nothing is sent or stored.
Scenario (invented)
A student (invented) plans the evening before a test. She plans to study until 01:15 and wake at 06:45. She also tracks a 90-minute session in which her phone interrupts her 10 times, each costing 3 minutes. A website tells her that "students using StudyBoost average 10 points higher, so it works", but gives no group size or details.
Tasks
Task 1 (3 marks)
How long would she sleep if she goes to bed at 01:15 and wakes at 06:45? Compare with 7 hours 30 minutes.
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Task 2 (4 marks)
Plan 3 blocks of 25 minutes with 5-minute breaks between them. Give the total time.
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Task 3 (3 marks)
How many minutes did the phone cost in the 90-minute session, and how many were focused?
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Task 4 (4 marks)
Use the five questions to say why the StudyBoost claim is weak, and what you would want to know.
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Rubric and model answer
Task 1: count the sleep (3 marks)
Model: 01:15 to 06:45 is 5 hours 30 minutes, which is 2 hours less than 7 h 30 min. A shorter night may cost recall.
Task 2: plan the blocks (4 marks)
Model: 3 x 25 = 75; 2 breaks x 5 = 10; total 85 minutes.
Task 3: cost the interruptions (3 marks)
Model: 10 x 3 = 30 minutes lost; 90 − 30 = 60 minutes focused.
Task 4: judge the advert (4 marks)
Model: no group size, no comparison group stated, no random assignment, no measure or timing given, and the seller benefits. A 10-point gap shows a link at best, not cause. Ask for the study details.
Marks so far: 0 of 14