📅 The Planning Fallacy

The tendency to underestimate the time and effort required for projects.

Interestingly, this is true even if the participant is aware of this bias. People routinely produce plans that are unrealistically close to best-case scenarios.

In product design, this is problematic when asking users to complete a process (such as a lengthy sign-up), which goes on longer than they had anticipated.

Overconfidence creates churn.

✅Conversion rates

  • If a process is taking much longer than the user anticipated, they may just give up.

✅Input quality

  • The user may not give up, but instead rush their answers, or just select default options.

✅Effort & motivation

  • It's incredibly demotivating to realise that something is taking much longer than expected.

✅Anxiety
✅Discomfort & frustration

  • Set clear and realistic expectations—don't let the user underestimate a process, and then get frustrated it's actually taking longer than they expected.

  • During the process, reset expectations—use progress indicators and milestones throughout long or complicated journeys.