- Identify related records: source groups, conversations, repeated inputs and synthetic descendants. Declare additional grouping fields from evidence rather than guessing from column names.
- Choose role fractions and a fixed seed. Use train for fitting, development for recipe/checkpoint decisions, calibration for fitting calibration and final for the independent comparison. Leave unused roles out of the recipe.
- Call
create_data_partitionwithname,request_key,source_cellandrecipe. The recipe acceptsseed,fractions,group_by, optionalstratify_byand explicitholdouts. - Follow the returned job through construction. Inspect actual role counts and group assignment; group sizes may prevent exact requested fractions.
- Verify the output cells against their intended consumer. Train/development roles receive training intent, while calibration/final roles receive evaluation intent. Native decision rows in calibration/final members are projected into input-only decisions and separate references. Other row formats are retained; changing intent alone does not convert them.
- Save the role cell IDs and use them explicitly in later jobs.
retry_data_partition only after inspecting a failed construction and the supported recovery action. It resumes the saved recipe rather than inventing another split.
For a data-first modelling project, retain the task definition and exact role cells in save_training_plan. Final answers must not guide recipe selection. See Data lineage and held-out evidence.