Measurement Standards

Δ‑B

  • Report baseline %, post %, Δ‑B in pp, relative change %, n, denominator, window, assignment, data source.

Time to First Behavior (TTFB)

  • Definition: elapsed time from exposure/start to first completion of target behavior.
  • Benchmarks: < 5 minutes B2C; < 1 day B2B pilot. State domain benchmarks when available.

Behavior Retention

  • Report D30 and D180 retention of the target behavior with cohorting and denominators.

Chain Risk Score (CRS)

  • CRS = min(BR_buyer, BR_champ, BR_user). Thresholds: 70 SMB; 80 regulated/safety‑critical.

Reporting rules

  • Label unsourced numbers as illustrative or link an Evidence Ledger ID.
  • Use behavior language, not “value” proxies. Always include denominator and window.

Instrumentation events

  • exposure_shown: surface, variant, timestamp
  • behavior_attempt_started: behavior_id, context, timestamp
  • behavior_completed: behavior_id, context, timestamp, success:true
  • behavior_abandoned: behavior_id, context, step, timestamp

TTFB = behavior_completed.timestamp − exposure_shown.timestamp for first completion. Δ‑B = completion rate in the window vs baseline, denominator explicit.

Example report (illustrative) 

Project: Onboarding flow v2 → target behavior “Upload all required documents in one session”
Segment: New applicants (web), first 14 days
Window: 30 days; Denominator: all exposed

Baseline completion: 28 pp (n=4,120)
Post completion: 43 pp (n=4,305)
Δ‑B: +15 pp (illustrative)

TTFB (median): 07:40 → 03:10 (illustrative)
Retention D30 of behavior: 9 pp → 17 pp (illustrative)

Notes: Failure points at step 3 reduced via checklist + one‑upload flow. Cohort construction documented. See Evidence: BS‑0001.

Why temporal design matters

Measurement outcomes depend on time windows and cadence. Meta-analytic evidence shows that studies with precise temporal hypotheses detect change more reliably. This supports our use of explicit windows, cohorting, and TTFB.

  • See Evidence:

BS-0017