{
  "protocol": "TADC-PP-01",
  "version": "0.1",
  "date": "2026-08-17",
  "status": "exploratory_pilot",
  "design": {
    "factors": {
      "external_domain": [
        "same",
        "cross"
      ],
      "relational_structure": [
        "near",
        "far"
      ]
    },
    "conditions": [
      "SN",
      "SF",
      "CN",
      "CF"
    ],
    "primary_directional_contrast": "K_CN - K_SF < 0"
  },
  "sample_targets": {
    "stage_A_calibration": 48,
    "stage_B_transition_pilot": 32,
    "note": "Feasibility targets only; not confirmatory power justification."
  },
  "stage_B": {
    "scored_trials_per_participant": 64,
    "trials_per_condition": 16,
    "practice_trials": 8,
    "counterbalance_lists": 4
  },
  "primary_outcomes": [
    "log_target_rt",
    "baseline_adjusted_transition_cost"
  ],
  "secondary_outcomes": [
    "target_accuracy",
    "transfer_probe_accuracy"
  ],
  "baseline_adjusted_cost": "K_ij = log(target_rt_ij) - median_stageA_log_solo_rt_target_j",
  "pilot_models": {
    "M0": "external_distance + surface_similarity + familiarity + target_baseline + source_accuracy + trial_index + random effects",
    "M1": "M0 + relational_distance"
  },
  "heldout_evaluation": [
    "participant-held-out",
    "target-held-out"
  ],
  "provisional_gates": {
    "domain_agreement_final_item": 0.8,
    "relation_icc_min": 0.6,
    "target_solo_accuracy_min": 0.7,
    "target_solo_accuracy_max": 0.95,
    "timeout_fraction_max": 0.15
  },
  "decision_states": [
    "GO",
    "REVISE",
    "KILL_CURRENT_OPERATIONALIZATION"
  ]
}