Defining a Clear Question

Why start with the question

A personal experiment is only as useful as its question. "Am I optimizing my sleep?" cannot be answered. "Do I fall asleep more easily on evenings when I read instead of looking at my phone?" can at least be compared. Most unhelpful self-experiments fail here, before any data is collected.

This guide is information only. It describes how to think about a question, not a program to follow, and it applies to ordinary, reversible habits. It is not for medicines, supplements, unapproved compounds, fasting or anything invasive; see when not to experiment.

What tracking shows and what an experiment adds

Tracking records what happens. An experiment changes one thing on purpose and compares periods with and without the change. A formal single-person version is called an N-of-1 trial, which observes outcomes in the same person during periods of exposure to an intervention and a comparator. [1] The difference is explained further in tracking vs experimenting.

Five parts of a clear question

1. One change you can describe. Something specific and ordinary, such as "reading for a while before bed instead of using my phone."
2. One outcome you care about. Often how you feel or function, not just a number. See selecting a meaningful outcome.
3. A fair comparison. Compared with what? Your usual routine is the natural comparison, which is why you need to establish a baseline first.
4. A realistic aim. A question about what changes for you is more honest than one about what is best for everyone. One person's result speaks to one person under particular conditions.
5. A reason to stop. Decide in advance what would make you drop the experiment, such as feeling worse, becoming anxious about the numbers, or noticing a symptom that worries you.

Two benign examples

In both cases the change is ordinary and reversible, and the outcome is something you can rate yourself. Public health advice already supports regular activity: the NHS, for example, describes brisk walking as a moderate-intensity activity and recommends adults aim for at least 150 minutes of moderate activity a week. [2] You are not testing whether activity is healthy. You are asking how a particular habit fits your own days.

Questions to avoid

• Diagnostic questions, such as "Do I have sleep apnea?" A consumer device cannot answer these; see consumer data vs clinical measurements.
• Questions about treating a condition. Talk with a clinician instead.
• Questions that need an unsafe change, such as fasting for long periods or using an unapproved compound.

Beware of the score that becomes the goal

Some people become preoccupied with tracker data. Clinicians have described patients seeking treatment for self-diagnosed sleep problems based on tracker readings, sometimes in a perfectionistic quest for ideal sleep. [3] If a question makes you more anxious, change the question or pause tracking.