Typing WPM / Accuracy Calculator 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

t5-062

Effect

Computation or source lookup only

Input and validation requirements

Zero elapsed time makes both gross WPM and net WPM undefined, so the instrument must reject that input. The specification also does not state the elapsed-time unit and does not explicitly define correct_chars from error_count, creating additional ambiguity.

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": {
    "characters_typed": 300,
    "elapsed_time_seconds": 120,
    "error_count": 15
  },
  "expected_outputs": {
    "gross_WPM": 30,
    "net_WPM": 22.5,
    "accuracy_percent": 95
  },
  "working": "minutes = 120 / 60 = 2; gross_WPM = (300 / 5) / 2 = 60 / 2 = 30; correct_chars = 300 − 15 = 285; accuracy = (285 / 300) × 100 = 0.95 × 100 = 95%; net_WPM = 30 − (15 / 2) = 30 − 7.5 = 22.5."
}

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-tranche5/tranche5-results.json