{
  "$schema": "https://terraevidence.com/evidence-record.schema.json",
  "recordId": "EP-PUB-008",
  "version": "1.0",
  "status": {
    "code": "reviewed-for-stated-scope",
    "label": "Reviewed for stated scope",
    "meaning": "Checked for the stated wording, sources, methods, context, limits, and review period; not universally proven."
  },
  "topic": "Mechanistic reasoning",
  "title": "A plausible mechanism is not a demonstrated outcome.",
  "claim": "A scientifically plausible pathway by which a product, amendment, organism, or practice could affect a soil or plant process is supporting evidence, but it should not be presented as proof that the proposed outcome occurred, was large enough to matter, was caused by the intervention, or will recur under field conditions.",
  "summary": "Mechanisms explain how an effect could occur and can strengthen or weaken a causal case. Outcome evidence must still show that the relevant exposure or dose occurred, the proposed pathway operated, the defined endpoint changed, appropriate comparisons support attribution, and the result fits the setting in which it is applied.",
  "evidenceSupports": [
    "Use mechanistic evidence to define a testable causal pathway, identify intermediate measurements, and predict what should occur if the pathway is operating. Seek evidence that the exposure, intermediate steps, and defined outcome occur at relevant magnitudes and times. Weigh the mechanism with direct outcome evidence, alternative causes, controls or comparisons, replication, uncertainty, and field context."
  ],
  "doesNotEstablish": [
    "A plausible pathway, ingredient function, laboratory reaction, biomarker, intermediate process, or explanatory story does not by itself establish that the final soil or plant outcome occurred, was caused by the intervention, was practically important, or will occur at a field-relevant dose. Absence of a known mechanism does not by itself refute an observed effect; an implausible or contradicted mechanism can weaken a claim."
  ],
  "sources": [
    {
      "sourceId": "EP-PUB-008-S1",
      "sourceType": "institutional-guidance",
      "institution": "United States Environmental Protection Agency",
      "title": "About Causal Assessment",
      "url": "https://www.epa.gov/caddis/about-causal-assessment",
      "relevance": "Describes causal assessment as evaluation of all relevant evidence, including alternative causes, rather than reliance on a single type of evidence."
    },
    {
      "sourceId": "EP-PUB-008-S2",
      "sourceType": "institutional-guidance",
      "institution": "United States Environmental Protection Agency",
      "title": "Evidence of Exposure or Biological Mechanism",
      "url": "https://www.epa.gov/caddis/evidence-exposure-or-biological-mechanism",
      "relevance": "Explains that exposure or mechanism evidence can strongly support a candidate cause but is not convincing alone because it does not show the exposure or mechanistic action was sufficient to cause the effect."
    },
    {
      "sourceId": "EP-PUB-008-S3",
      "sourceType": "institutional-guidance",
      "institution": "United States Environmental Protection Agency",
      "title": "Step 5: Identify Probable Causes",
      "url": "https://www.epa.gov/caddis/step-5-identify-probable-causes",
      "relevance": "Evaluates candidate causes through the strength and consistency of evidence across multiple causal characteristics and preserves uncertainty when evidence is incomplete."
    }
  ],
  "scope": {
    "reviewedPeriod": "2026-08",
    "applicability": [
      "Evaluating mechanism-based claims about soil amendments, products, practices, organisms, and biological or chemical processes."
    ],
    "limitations": [
      "Does not rank all mechanistic evidence; its weight depends on directness, measurement, relevance, consistency, dose and timing, and its relationship to the defined outcome.",
      "Does not imply that mechanisms are unimportant or that a supported outcome requires a fully known mechanism, and does not provide personalized fertilizer, lime, amendment, crop, environmental, pest-control, or safety recommendations."
    ],
    "openQuestion": "Which intermediate measurements most reliably predict meaningful field outcomes for specific soil and plant processes?"
  },
  "useBoundary": "This reviewed record supports careful reasoning about mechanisms and outcomes. It does not endorse a product, practice, amendment, or organism; prove that a proposed pathway produced a meaningful field result; or provide personalized fertilizer, lime, amendment, crop, environmental, pest-control, or safety recommendations. Preserve the proposed pathway as a testable explanation and seek direct, compatible outcome evidence and qualified guidance when a consequential decision requires it.",
  "humanReadableUrl": "https://terraevidence.com/earth-project-reviewed-foundations#ep-pub-008",
  "machineReadableUrl": "https://terraevidence.com/evidence-records/ep-pub-008.json",
  "revision": {
    "version": "1.0",
    "publishedDate": "2026-08-17",
    "lastReviewedPeriod": "2026-08"
  }
}