Δ‑B

Definition: Δ‑B is the change in the target behavior rate after an intervention.

Reporting standard

Always report:

• Baseline rate, post rate, and Δ‑B in percentage points.
• Relative change in percent for context.
• Sample size, assignment method, and denominator.
• Measurement window and data source.
• Segment by the limiting BSM component if known.

Formulas

• Δ‑B (pp) = Post% − Baseline%
• Relative change (%) = (Post% − Baseline%) / Baseline% × 100

Examples

• Example 1: Baseline 22% complete the behavior; post 36% do. Δ‑B = +14 pp. Relative change = +63.6%.
• Example 2: Baseline 5% → post 7%. Δ‑B = +2 pp. Relative = +40% with n and window explicit.

Counterexample: A proxy metric (e.g., page views) increased, but the target behavior (e.g., task completion) did not change. Report Δ‑B for the target behavior, not the proxy.

Add a claim to the Evidence Ledger when you report Δ‑B.