Capstone: Designing and Critiquing a Real Experiment

The hypothesis is framed in a form that could genuinely fail: "instrumental background music produces no significant difference in next-day recall scores compared with silence." A real result — in either direction — can disconfirm it, satisfying Popper's own falsifiability criterion.

This single study tests one specific hypothesis. It is not, by itself, a theory — it would need to be one small, repeated piece of evidence feeding into a broader theory (e.g. cognitive load theory) only after independent replication, never treated as confirming that broader theory on its own.

Independent variable: music vs. silence during study. Dependent variable: next-day recall test score. Controlled: identical study material, identical study duration, identical test. Control group: the silence condition. Randomization: participants randomly assigned to condition, not self-selected.

Participants can't be blinded to their own condition — they know whether they're hearing music. An honest limitation, not a flaw to hide. But the researcher scoring each recall test can be blinded to which condition each participant was in, preventing the same kind of expectation-driven scoring bias Chapter 4's placebo material covered.

Sample size is set in advance via a real power calculation, not by "running until significant" — the exact flexible-analysis pattern behind the Open Science Collaboration's own 36% replication rate. The full analysis plan is fixed before data collection begins.

What result would count against the hypothesis is written down in advance — and if the result comes back null or unexpected, no new, untested sub-group or post hoc statistical construct will be invented to rescue it, the exact ad hoc pattern that discredited the real Mars effect.

The introduction and methodology are submitted for real peer review before data collection — the Center for Open Science's own Registered Reports format, which measurably cut psychology's suspicious 96% "positive result" rate down to 44% by removing the incentive to chase a significant finding.

Because the study is a Registered Report, publication doesn't depend on the result — closing off the file-drawer problem before it can happen. In advance, the plan also names what would trigger a real correction (a fixable error), an expression of concern (a serious, unresolved doubt), or a full retraction (a genuinely invalidated result) if a flaw were discovered after the fact.