Methodology: How Tools Are Built and Checked

A plain explanation of how tools on this site get chosen, documented, sourced, tested, and corrected — and what part AI/automation plays in that.

1. How tools get chosen

Tools are chosen to solve a practical calculation, conversion, reference, or planning task — something a person is actually trying to figure out, not a topic picked to fill out a category. There's no formal market research, user panel, or traffic-based prioritization process behind these choices; tool ideas come from genuine everyday needs and from gaps noticed while building out a category.

The site has particular depth in sewing, knitting, crochet, and other crafts, handmade-business tasks (pricing, costing, quoting), home and project planning, and everyday utilities — that's a deliberate focus area, not an accident of what happened to get built first. See the About page for more on why the craft section exists.

2. How calculations and rules are documented

Where practical, a tool's page should document: what it calculates, the formula or conceptual method behind it, the assumptions it makes, its limitations or common mistakes, and a worked example when that's genuinely useful. That's the current editorial standard new and updated pages are held to.

Not every page on this site has been brought fully up to that standard yet — this is an active, ongoing process across a large site, not a claim that every historical page already satisfies every one of those points. Pages get reviewed and improved in batches rather than all at once.

3. Sources for facts that change over time

Some calculators depend on facts that change outside this site's control — fees, rates, policies, thresholds, or regulations set by a third party (a marketplace, a government agency, an industry standard). Where that applies, the page should cite an authoritative or primary source — ideally the official documentation from whoever actually sets the number — rather than a second-hand summary.

If an important changing fact can't be confidently verified against a real source, that page may be temporarily held out of search indexing until it's resolved, rather than publishing a guess. Most tools on this site don't depend on this kind of external fact at all — a gauge formula or a unit conversion doesn't need a "source" the way an Etsy fee percentage does, and this requirement only applies where it's actually relevant.

4. How tools get checked

Tools may be checked using known worked examples, boundary or threshold cases (like a fee structure that changes at a specific dollar amount), unit-conversion equivalence checks (confirming a value converts correctly and back again), rounding-behavior checks, and manual testing in a browser.

For tools where automated regression tests have been added — currently including the Etsy Fee Calculator, the general Gauge Calculator, and several everyday utilities (Password Generator, Unit Converter, Percentage Calculator, Word Counter) — those tests run against the same logic the live page uses, and are re-run whenever that logic changes. That is not yet true of every tool on the site; automated testing is being added incrementally, not applied everywhere at once.

5. What a "Last Verified" date means

When a page shows a Last Verified date, it means the specific externally-changing facts or sources that page depends on were checked against a real source as of that date. It is not a promise that the information can never change afterward — policies, fees, and rates get updated by the organizations that own them, sometimes without much notice.

A time-sensitive page should be reviewed again when there's reason to think its underlying source, policy, or rate has changed, or when the Last Verified date has become old enough that the fact is plausibly stale. There is currently no automated, scheduled system that monitors external sources for changes and re-verifies pages on its own — that kind of ongoing quality gate is planned but not yet built.

6. Reporting a correction

If you find a calculation problem, a broken tool, a stale fee or rate, a typo or content error, or an accessibility/usability problem, the Contact page is the way to report it — use the Bug Report option for something broken or wrong, or Suggestion for an improvement to something that already works. Every submission is read, and corrections get made.

7. Who's accountable for what's published

The Useful Pages is published by Sassy Pup Studios LLC (see the About page). There is a human owner responsible for what goes live on this site — this is a small, independently run site, not a large editorial operation, and there is no claim of licensed professional review or independent expert sign-off on any tool or page. Automation and AI tools can assist with the work described below, but the decision to publish, and the responsibility for what's published, stays with a human.

8. AI and automation, honestly

AI and automation tools materially assist in building and maintaining this site — drafting page content, writing and updating calculator code, generating and running tests, reviewing the site's own inventory for gaps or problems, and flagging things that look wrong. Work produced this way is not automatically treated as correct just because it was generated; it goes through the review and publication process described above before it counts as part of the site. Claims that depend on an outside source — a fee, a rate, a policy — are checked against that actual source rather than trusted on the strength of how confidently they were written.