This page explains the structure of the branching experiment in plain language.
A parent is the earlier attempt from which a child starts. A root has no parent. A child copies the parent program and gets one improvement opportunity.
The 14 training cases are visible to Pi. They show the task shape and let Pi develop its first solution.
The 10 validation cases are hidden from Pi. The orchestrator uses their scores to decide which branch should receive an improvement.
The 12 holdout cases are hidden from Pi and branch selection. They are used only for the final generalization comparison.
This study is a local simulation, not a real Fabric execution. The onboarding cases are synthetic JSON fixtures, and Pi writes local solution.py programs. It does not yet run real Fabric Business Processes, Worker traces, PDFs, scanned images, or document-extraction tools. The next study should connect the same branching and replay design to isolated customer-32 Fabric development BPs with synthetic PDFs and images.