{
  "id": "four-fit-hierarchy",
  "title": "Four-Fit Hierarchy Evidence-Gate Spec",
  "version": "2.0.0",
  "status": "pre-release",
  "support_status": "unsupported",
  "status_note": "This public draft has no named toolkit maintainer or support commitment. It does not supply universal thresholds or viability verdicts.",
  "canonical_url": "https://behavioralstrategy.com/glossary/four-fit/",
  "license": "CC-BY-4.0",
  "description": "Four-Fit is the ordered validation hierarchy of Problem Market Fit, Behavior Market Fit, Solution Market Fit, and Product Market Fit.",
  "sequence": [
    "problem_market_fit",
    "behavior_market_fit",
    "solution_market_fit",
    "product_market_fit"
  ],
  "threshold_policy": {
    "rule": "Every quantitative threshold must be pre-registered for the named domain, population, context, stakes, measure, and observation window before results are reviewed.",
    "missing_threshold": "Report the evidence or threshold as incomplete. Do not substitute a universal pass rule or infer viability.",
    "observed_validation": "A recorded threshold comparison is one input to a fit decision; observed behavior and domain evidence remain required."
  },
  "behavior_fit_assessment_contract": {
    "version": "2.0",
    "description": "The Behavior Fit Assessment is a practitioner decision tool for comparing candidate behaviors across Dispositional Fit, Capability Fit, and Context Fit.",
    "legacy_alternate_name": "Identity Fit is the legacy alternate name for Dispositional Fit only.",
    "epistemic_label": "It is not a validated measurement instrument.",
    "decision_rule": "Treat the minimum dimension as a bottleneck and prioritization heuristic; it is not a deterministic probability of behavior.",
    "starting_threshold": "A score of 6 out of 10 on each Behavior Fit Assessment dimension is a starting threshold that must be calibrated by domain, population, context, stakes, and observed behavior."
  },
  "gates": [
    {
      "id": "problem_market_fit",
      "name": "Problem Market Fit",
      "question": "Does the defined population actively seek solutions for this problem?",
      "required_evidence": [
        "Observed solution-seeking behavior in the defined population and context.",
        "Recorded willingness signals such as time, money, or effort.",
        "Workarounds or prior attempts, including counterevidence."
      ],
      "decision_requirement": "Apply only thresholds pre-registered for the named domain and population. Record uncertainty and counterevidence.",
      "outputs": ["problem_definition", "population_definition", "evidence_of_solution_seeking", "pre_registered_decision_rule"]
    },
    {
      "id": "behavior_market_fit",
      "name": "Behavior Market Fit",
      "question": "Can and will the population perform the target behavior in realistic contexts?",
      "required_evidence": [
        "Observed completion of the target behavior in realistic contexts.",
        "Provisional Dispositional Fit, Capability Fit, and Context Fit comparisons with evidence.",
        "A domain- and population-specific validation rule registered before results are reviewed."
      ],
      "decision_requirement": "Use BFA ratings to prioritize bottlenecks and tests. Do not treat a minimum rating or starting threshold as a universal probability or pass rule.",
      "outputs": ["target_behavior_definition", "context_definition", "bfa_comparison", "observed_behavior_results", "pre_registered_decision_rule"]
    },
    {
      "id": "solution_market_fit",
      "name": "Solution Market Fit",
      "question": "Does the solution measurably enable the validated target behavior by reducing friction and increasing payoff?",
      "required_evidence": [
        "A defined behavior chain and friction hypotheses.",
        "Observed behavior with and without the relevant solution conditions where feasible.",
        "Pre-registered measures, thresholds, and observation windows appropriate to the domain and population."
      ],
      "decision_requirement": "Do not apply universal time-to-behavior, completion-rate, or assistance rules.",
      "outputs": ["behavior_chain_map", "friction_evidence", "enablement_results", "pre_registered_decision_rule"]
    },
    {
      "id": "product_market_fit",
      "name": "Product Market Fit",
      "question": "Does the target behavior sustain in market conditions with viable economics or program operations?",
      "required_evidence": [
        "Cohort-defined behavior persistence over domain-relevant windows.",
        "Viability evidence for the relevant economics or program operations.",
        "Pre-registered thresholds and observation windows for the named domain and population."
      ],
      "decision_requirement": "Do not transfer retention windows or thresholds across domains without a documented calibration basis.",
      "outputs": ["retention_report", "cohort_definitions", "economics_or_operations_evidence", "pre_registered_decision_rule"]
    }
  ],
  "evidence_ids": [],
  "limitations": [
    "The specification checks evidence readiness and sequence; it does not make a universal viability claim.",
    "Thresholds, measures, and time windows must be calibrated and pre-registered for each use context."
  ]
}