Methodology

Formula selection

Each calculator uses a single, documented formula drawn from our accepted source hierarchy (see our Sources page). When multiple valid formulations exist, we choose the one most appropriate for the calculator's audience and document the choice in the calculator's page contract.

Source hierarchy

We prioritize government and intergovernmental sources, university and peer-reviewed publications, standards bodies, established textbooks, and reputable professional organizations — in that order. We do not cite sources we have not actually consulted.

Independent verification

Before publication, each calculator is verified against at least two independent reference examples. Implementation code is checked against the documented formula, and results are compared to hand-calculated or textbook values.

Reference examples

Every calculator includes built-in example datasets with known correct outputs. These examples serve as regression tests and as learning aids for users exploring the tool.

Edge-case testing

Calculators are tested at boundary conditions: empty inputs, single values, duplicate values, extreme magnitudes, and common invalid inputs. Error messages must be specific and actionable.

Rounding policy

Display precision is documented per calculator. Intermediate calculations use full floating-point precision; final displayed values are rounded using standard half-up rounding unless a specific field convention requires otherwise. The number of decimal places shown is stated in each calculator's contract.

Unit handling

Each calculator documents whether it expects raw numbers, labeled units, or unitless values. Unit conversions, when supported, are shown as explicit steps rather than applied silently.

Correction process

If you believe a calculator contains an error, contact us at hello@calclume.com. Verified errors are corrected promptly, with the correction date noted on the affected page.

Update process

Calculators are reviewed on a scheduled basis and updated when reference standards change or when improved formulations become available. The last reviewed date appears on each published calculator page.

Current commitments vs. future aspirations

Current production: Methodology documentation, source hierarchy, calculator page contract, UI architecture, and the Mean Absolute Deviation Calculator are published. Calculations run locally in the browser.

Future: Additional statistics calculators, broader regression suites, peer review by subject-matter contributors, and versioned formula changelogs are planned but not yet complete.