Testing Methodology — How We Test Hardware
Test period
A minimum of 60 days of real use, 90 as the target. Shorter tests miss battery drift, firmware failures and how a device survives everyday life.
What we measure
Where possible we compare the device against a reference: sleep trackers against home polysomnography, CGMs against fingerstick readings, heart rate against a chest strap. We report agreement as a percentage of epochs or measurements, never as a vague impression.
Where the hardware comes from
We buy it. If a manufacturer lends a unit, we say so at the top of the review. We do not let manufacturers approve our text and we do not send them a version before publication.
Scores
A 1–10 score with explicit criteria: measurement accuracy, comfort, battery, software, value for money. Every review ends with a “who it’s for / who it isn’t for” section.
Corrections policy
We fix factual errors and record the date and scope of the change at the foot of the article. We do not edit silently.
How we label evidence
Hardware reviews describe our measurements. Health claims describe published research. Those are two different categories and we do not mix them in one sentence.
Every health claim carries an evidence level from the scale explained in the supplements guide. Every measurement of our own carries its method, period and reference point.
Conflicts of interest
We earn from affiliate links and say so on every page that carries them. Commission does not depend on the verdict: we are paid the same whether we recommend a product or advise against it.
We do not accept paid reviews or sponsored articles. If that ever changes, such material will be labelled at the top of the page rather than in the footer.
The corrections policy in practice
We fix factual errors and add the date and scope of the change at the foot of the article. Typos are fixed without a note. A change of verdict in a review is always flagged, together with the reason.
The rules we use to build step-by-step instructions are in the protocols section, and how we treat consumer device data is covered in sleep and longevity.