Define and frame
Classify id, group, study_hours and stress_rating by measurement type. Explain why an identifier is not a quantitative outcome.
Scenario: The shared synthetic CSV contains 36 records, seven columns and three missing stress ratings.
Use the fictional dataset if the question refers to it. Always show your reasoning; an exact number without context is not enough. The four written tasks are teacher-assessed. The self-check below is formative and does not affect the 20-mark assignment.
Written problem set
Calculate or apply
With three missing stress values out of 36, calculate the missingness percentage and valid n.
Evaluate the design
Give two plausible biases in self-reported study hours and one mitigation for each.
Interpret and communicate
If high-stress participants disproportionately omit ratings, how might a complete-case mean be affected?
Standard scoring guide
Each written task is worth 5 points: correct key idea (2), justified application or computation (2), and a clear statement with limits (1). This original rubric is not official UCL assessment.
Formative self-check · 4 questions
Choose one answer for each item, then check the feedback. Answers and explanations are available on this public study page; the separate written-task instructor key is private.