1. Start with the need
We define the question the guide can answer and the conditions that could change the answer. A backup-power guide, for example, should begin with what must keep running and for how long—not with a list of batteries.
2. Build the evidence base
We look first for public primary sources: government guidance, certification records, standards bodies, product manuals, and current manufacturer specifications. Independent reporting and specialist sources can add context. Community discussions may reveal questions worth investigating, but they do not establish that a claim is true or common.
3. Check what each source proves
A specification can confirm capacity; it cannot prove that a product is best. Safety guidance can identify a hazard; it cannot diagnose your home. When the available information does not support a firm answer, we say so.
4. Compare what matters in real use
We look at fit, capacity, compatibility, upkeep, ongoing cost, ease of use, and reasons an option may not work for you. Sometimes the sensible answer is to keep what you have, fix another problem first, or buy nothing.
5. Tell you how we did the work
Our current guides use published research and product information unless a page specifically describes hands-on testing. When we test something or consult a specialist, the guide should explain what was checked and what the work could not prove.
6. Keep the guide current
Substantial guides show a review or update date. We revisit them when guidance, product availability, specifications, or our conclusion changes. When a reported error is confirmed and matters to the advice, we correct the page.