When two studies look good, the mistake is comparing by headline: total payment, prestige, novelty.
Real life breaks studies through timing, travel, and at home task deadlines. Compare those first.
A comparison method that survives a bad week
Use a simple grid. Rate each category 1 to 5. Higher means harder. Add totals. If totals tie, choose the study with the looser timing windows.
- Timing: strictest window and frequency.
- Travel: distance and time of day.
- At home tasks: frequency and deadlines.
- Procedures: intensity and frequency.
- Operations: clarity and written instructions.
- Payment: schedule and timing.
Tie breakers
Tie breakers that matter: written schedule clarity, hardest at home task, and payment predictability.
Predictability beats total for many participants because it reduces stress.
Questions to ask when comparing
- If a visit slips, what is the recovery plan?
- What at home task is hardest to do on time?
- Is any payment held until completion and what counts as completion?
- What is the most common surprise for new participants?