Week 7: In-Class Test 1 (20%)

22 April 2026

This week is the first in-class test, covering material from weeks 1–6.

Test 1 answers (released)

Suggested answers to the 2026 in-class test are now available: Test 1 Answers (PDF). These are model answers, not the only acceptable phrasing — credit was awarded for any defensible reasoning that addressed each part of the question.

What is covered

• Causal questions, contrasts, target populations, and unobservability (week 1)
• Causal diagrams: elementary structures (week 2)
• Confounding bias structures (week 3)
• Selection bias and measurement bias (week 4)
• Average treatment effects and the three fundamental assumptions (week 5)
• Effect modification and CATE (week 6)

Format

• Duration: 1 hour 50 minutes
• Closed book, one A4 sheet of notes permitted, no devices
• Bring a pen or pencil
• Location: EA120 (the usual seminar room)

Reminders

• Bring a pen or pencil
• You may bring in one A4 sheet with notes.
• No electronic devices permitted during the test.
• Arrive on time. The test begins at 14:10.
• Write clearly; illegible answers cannot be marked.