How to Preregister a Self-Experiment in Fifteen Minutes
Write the question, the measure and the verdict rule before day one. A seven-step template borrowed from research preregistration, sized for one person and one notebook.
In this article3 sections
An experiment on yourself has one built-in problem: you also run the scoring. After 30 days you will remember the mornings that fit the story. Researchers call the cure preregistration, which Nosek and colleagues define in PNAS (2018) as setting the research questions and analysis plan before the outcomes are seen. Here is that idea shrunk to a notebook page.
The seven steps
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Write the question as one sentence. Name the change and the outcome. “Does a 6:30 alarm leave me less foggy at 10:00 than a 7:00 alarm?” works. “Does waking early help me?” does not.
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Pick one outcome and the moment you will record it. A 1-to-5 fog rating at 10:00 every day takes ten seconds. A rating is a remembered number, so pair it with something recorded in the moment, such as the time you silenced the alarm; Feynman’s maze rats are the cautionary tale. Two outcomes double the chances that one of them looks good by luck.
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Fix the schedule. For example, 10 days at 6:30 and 10 days at 7:00, with the order set by a coin flip, and the first 3 days of each block thrown out. A slow-adapting change such as a new wake time bleeds from one block into the next, which is why the blocks are shorter and have a washout, and one reason a 30-day sleep experiment is a weak test of wake times.
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Write the verdict rule. “If my average rating is at least 1 point better on one schedule, I keep it.” Pick the number now, while it costs nothing to be honest.
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List exclusions. Illness, travel and any night under five hours do not count. Decide before you see a single result.
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Date-stamp it and hand it to someone. Email the plan to a friend or paste it in a dated note. The date is what keeps the plan honest; the friend is what makes you open the result.
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Run it, then apply your rule. Resist peeking at the halfway average. When it ends, compare the numbers with the rule you wrote. Anything else you spotted along the way is a lead for experiment two.
Why bother on a notebook page?
Without the plan, you can change the outcome, the dates or the rule after you have seen the numbers, and each change nudges the answer toward what you hoped. A written plan removes those options. One caution runs the other way: a daily rating is a measurement too and may nudge the behavior, a risk spelled out in the glossary entry on asking about intent. Note that in the plan.
Questions
What is preregistration? Preregistration means defining the research questions and analysis plan before observing the outcomes. Nosek, Ebersole, DeHaven and Mellor (PNAS, 2018) argue it separates predictions from postdictions, because mistaking hindsight for a test makes findings look stronger than they are. For one person it shrinks to a page: question, measure, schedule, verdict rule, exclusions.
Can one person’s experiment prove anything? It can show a large, fast, reversible effect for that person. Slow-to-adapt changes such as a new wake time carry over from one condition to the next and blur the comparison.
What if the result lands between yes and no? Then the rule you wrote decides: with a 1-point rule, a 0.6-point gap is a no. Treat it as a lead and design a sharper second round, instead of lowering the bar after the fact.