Define the assignment
Audience: an operational manager. Deliver a reproducible analysis, a source-validation log, one useful visual or table and a 250-word decision note. Suggested duration: 60–90 minutes. All source records are fictional.
Investigation plan
Check campaign-period uniqueness and count domains; aggregate counts/costs; calculate ratios from totals; compare channels and disclose attribution limits.
Exercises
1. Write the metric definition and grain. 2. Validate keys and units. 3. Calculate independently using two methods. 4. Show excluded/exception records. 5. Write one recommendation and one unanswered question.
Worked control totals
Spend EUR500, clicks 900, attributed conversions 54, conversion rate 6%, spend/conversion EUR9.26. Search spend 270/27=10; Social 180/9=20; Email 50/18=2.78 EUR/conversion.
Interpretation and limitations
No order values, user overlap or randomized comparison are provided. Do not claim ROAS, profit or causal lift. A strong answer proposes the next evidence needed and avoids presenting a descriptive result as an established cause.
Self-review rubric
Score 0–2 each for scope, arithmetic, validation, explanation and reproducibility. For each score link to a concrete artifact. A total score is a self-check, not certification or employment evidence.
Try the activity before reading its reference. Keep your sources, commands and assumptions with your work. Companion activities are unsaved self-practice and do not award a certificate or change lesson progress.