{
  "handle": "FractionalMetaModel",
  "ref": "FractionalMetaModel#3eca",
  "stub": "3eca",
  "semaId": "sema:FractionalMetaModel#mh:SHA-256:3eca15b2980bb7a1d6b64d65d940a7ef05df23858c862623417c3dceb72471e7",
  "layer": "Infrastructure",
  "category": "Data Structures",
  "gloss": "A model at the level of the solution that partly implements several models at once",
  "mechanism": "Three kinds of meta-model differ in where they sit. A hierarchical meta-model goes one level up and keeps only data types and relations, so its domain cannot be read from it; a geologic map meta-model, or a neural network described as a meta-model, is of this kind. A domain-specific language goes one level down and restricts a general language to one domain. A fractional meta-model sits at the level of the solution itself and implements one model fully while implementing parts of others: k of the n components a function needs are in place. The simplest case is a {{computational_channel}}, where generated but rejected inputs are fractionally implemented functions that a change to the acceptor would complete. Full implementation is the special case k equals n.",
  "invariants": [
    "The domain can be read by inspecting a fractional meta-model",
    "Full and absent implementation are the limiting cases k = n and k = 0"
  ],
  "failureModes": [
    "Calling a data hierarchy a meta-model and expecting it to hold domain information",
    "Leaving fractions unmeasured, so neither their cost nor their readiness is known"
  ],
  "ring": 2,
  "tier": 2,
  "aliases": {
    "computational_channel": "ComputationalChannel"
  },
  "buildsOn": [
    {
      "handle": "ComputationalChannel",
      "type": "references",
      "alias": "computational_channel",
      "url": "/knowledge-graph/ComputationalChannel/",
      "json": "/knowledge-graph/ComputationalChannel.json"
    }
  ],
  "usedBy": [
    {
      "handle": "StressorIncidenceMatrix",
      "type": "composes_with",
      "alias": "fractional_meta_model",
      "url": "/knowledge-graph/StressorIncidenceMatrix/",
      "json": "/knowledge-graph/StressorIncidenceMatrix.json"
    }
  ],
  "sources": {
    "research": [],
    "works": [
      {
        "kind": "book",
        "label": "On the Origin of Risk",
        "note": "(Timlett 2025), ch. 2 (geologic map meta-model), Technical appendix I (fractional meta-models, Fig. 25-26)",
        "url": "/research/on_the_origin_of_risk/"
      }
    ],
    "homePage": false
  },
  "url": "/knowledge-graph/FractionalMetaModel/",
  "graphUrl": "/knowledge-graph#FractionalMetaModel",
  "directory": "/knowledge-graph/patterns.json"
}