# Separate the evidence Distinguish product change, user evidence and organisational outcome without assuming causality. Duration: 5 min More output or use can support an outcome hypothesis without proving organisational value. ## decision-ready-review-m1-l2-reading ### Keep evidence layers visible Ask what changed in the product, for users and for the organisation. State the hypothesised links and alternative explanations. Usage is not automatically value; revenue movement is not automatically caused by the feature. UK Government guidance recommends choosing measures for the question and combining performance data with user research. The Magenta Book adds theory-of-change, context and attribution discipline. Both sources have public-sector scope. **Failure mode:** every completed story is labelled value. Demonstrate the output, then test the user and outcome assumptions separately. ### Worked example and transfer practice All examples below are fictional teaching material. Use synthetic notes; no workplace or personal data is required or uploaded. **Three evidence layers in one record.** Synthetic library evidence: confirmations were sent for 40 reservations (output); 30 of 36 responding borrowers identified the collection date (user evidence); failed collections fell from 8 of 40 to 4 of 40 (service outcome). These are two comparison windows, each with 40 reservations. Volunteer staffing also changed, so the decline does not establish attribution. The four nonrespondents also limit the understanding claim. **Try before reading the guide:** Calculate the two failed-collection shares, name a competing explanation, and propose evidence needed before expanding the trial.
Practice review guide The shares are 20% and 10%, a 10-percentage-point difference, not proof of causation. Check comparable windows, borrower mix, staffing and missing responses. More messages sent alone cannot establish service value.
## decision-ready-review-m1-l2-check Public answer keys are intentional.