Sample Size / Power Calculator (clinical study education) implementation

Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

Record owner

Guth Instruments

Lifecycle

verified-clean

Evidence ID

t6-109

Effect

Computation or source lookup only

Input and validation requirements

The edge vectors expose undefined or invalid outputs unless the calculator validates zero effect size and zero variance. The branch and convention probes also produce materially different sample sizes when outcome type or alpha sidedness is interpreted differently.

Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

{
  "inputs": {
    "design": "two-arm means, equal allocation",
    "sigma": 10,
    "sigma_units": "units",
    "delta": 5,
    "delta_units": "units",
    "alpha": 0.05,
    "power": 0.8,
    "z_(1-alpha/2)": 1.96,
    "z_power": 0.841621
  },
  "expected_outputs": {
    "raw_n_per_group": 62.792642,
    "required_n_per_group": 63
  },
  "working": "β=1−0.80=0.20. z-sum=1.96+0.841621=2.801621. Square: 2.801621²=7.849080. Variance factor: 2σ²/Δ²=2×10²/5²=200/25=8. Raw n=8×7.849080=62.792642. Round up: ceil(62.792642)=63 per group."
}

Other records

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json
• evidence-tranche6/tranche6-results.json