{ "model": { "rank": 2332, "code": "thing-q40936", "model_id": "vr.tr.ph", "name": "pH", "purpose": "Let an agent explain pH and its definition, relay measurement methods and standards, describe typical values and their significance in domains such as blood, soil and paper, and route personal health questions to clinicians.", "family": "Thing Registry", "category": "Cross-cutting context", "status": "research-draft", "kind": "thing", "plane": "XCT", "domain": "XCT.QLT", "industry": "", "version": "", "url": "/models/thing/q40936/", "tier": 2, "score": 109, "payload": { "layer": "wikidata", "aliases": [ "pH of Urine", "pH value of paper", "circumneutral", "arterial blood pH", "soil pH", "pH of blood" ], "aliasCount": 6, "merged": 6, "knownIn": 109, "facets": null, "markers": [], "lexicalClass": "", "senseRank": null, "alsoRegisteredAs": null, "source": { "dataset": "wikidata", "item": "Q40936", "url": "https://www.wikidata.org/wiki/Q40936", "license": "CC0 1.0" } }, "research": { "vercy": "1.0-draft", "publication": { "status": "research-draft", "adjudicationStatus": "unreviewed", "publishableCanonical": false, "generatedAt": "2026-09-12T22:59:37Z", "providers": [ "Claude" ], "breadth": "written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify", "pass": 2, "wave": 3, "engine": "claude" }, "metaModel": { "id": "THING-Q40936", "registryId": "vr.tr.ph", "name": "pH", "version": "0.2.0-wave.3", "entryKind": "thing", "family": "Thing Registry", "domain": [ "XCT.QLT" ], "status": "research-draft" }, "canonicalUrl": "https://ver.cy/models/thing/q40936/", "model": { "registry_id": "vr.tr.ph", "name": "pH", "purpose": "Let an agent explain pH and its definition, relay measurement methods and standards, describe typical values and their significance in domains such as blood, soil and paper, and route personal health questions to clinicians.", "definition": "A logarithmic measure of the acidity or alkalinity of an aqueous solution, defined as the negative decimal logarithm of the hydrogen ion activity, with 7 neutral at 25 degrees Celsius, lower values acidic and higher values alkaline; pH is measured with electrodes or indicators, is central to chemistry, biology, medicine, agriculture and industry, and specific values such as blood pH, urine pH, soil pH and the pH of paper are monitored for health, growth and preservation.", "what_it_is_for": "Quantifying acidity and alkalinity.", "affordances": [ "explain the definition and scale", "relay measurement methods", "relay typical values by domain", "route personal health questions" ], "distinguishing_features": [ "Logarithmic", "Temperature dependent", "Measured by electrode or indicator", "Domain-specific reference ranges" ], "appearance": "Not a visible object; a number on a meter or a colour on indicator paper.", "visual_identification": [ "Negative log of hydrogen ion activity", "Scale around 0 to 14 in water", "Acidity in food labelling and total acidity are related but different measures" ], "physical_properties": [ { "quantity": "neutral pH at 25 degrees C", "typical_range": "7.0", "unit": "pH", "note": "" }, { "quantity": "normal arterial blood pH", "typical_range": "7.35-7.45", "unit": "pH", "note": "" }, { "quantity": "circumneutral range", "typical_range": "about 6.5-7.5", "unit": "pH", "note": "in ecology" } ], "families_and_kinds": [ "pH of solutions in chemistry", "blood and urine pH in medicine", "soil pH in agriculture", "pH of natural waters", "pH of paper and materials in conservation", "pH scales in non-aqueous systems" ], "related_models": [ { "relation": "is a kind of", "target": "logarithmic quantity", "why": "in registry terms" }, { "relation": "is a kind of", "target": "chemical quantity", "why": "in registry terms" }, { "relation": "measures", "target": "acidity", "why": "and alkalinity" }, { "relation": "is measured by", "target": "pH meter", "why": "the instrument" } ], "identifiers": [ { "scheme": "IUPAC definition", "value_or_pattern": "pH", "note": "based on hydrogen ion activity" } ], "standards_and_regulation": [ "IUPAC recommendations on pH", "ISO and national standards for pH measurement and buffers", "Drinking water and environmental pH limits", "Clinical reference ranges" ], "failure_modes_and_hazards": [ "Calibration and temperature errors", "Misreading the logarithmic scale", "Agents interpreting personal test results" ], "in_scope": [], "out_of_scope": [], "characteristics": [] }, "sources": [], "structure": { "bundles": [ { "id": "define", "name": "Define", "description": "What pH is.", "rationale": "Definition.", "layers": [ { "id": "definition", "name": "Definition", "description": "Definition and scale.", "findings": [ { "id": "definition-finding", "name": "Definition", "description": "Definition.", "questions": [ { "text": "What is pH, how is it defined, and why is the scale logarithmic?", "kind": "definition" }, { "text": "Is the question about pH or about a related acidity measure?", "kind": "boundary" } ] } ] }, { "id": "chemistry", "name": "Chemistry", "description": "Chemistry of pH.", "findings": [ { "id": "chemistry-finding", "name": "Chemistry", "description": "Chemistry.", "questions": [ { "text": "How do acids, bases and buffers determine pH, and how does temperature affect it?", "kind": "definition" }, { "text": "Which entry fits acid-base chemistry?", "kind": "action" } ] } ] } ] }, { "id": "measure", "name": "Measure", "description": "Measurement.", "rationale": "Computation.", "layers": [ { "id": "methods", "name": "Methods", "description": "Methods.", "findings": [ { "id": "methods-finding", "name": "Methods", "description": "Methods.", "questions": [ { "text": "How is pH measured with electrodes and indicators, and how are meters calibrated?", "kind": "provenance" }, { "text": "Which references are standard?", "kind": "provenance" } ] } ] }, { "id": "compute", "name": "Compute", "description": "Calculation.", "findings": [ { "id": "compute-finding", "name": "Compute", "description": "Compute.", "questions": [ { "text": "How is pH calculated from concentrations, and how are values converted?", "kind": "action" }, { "text": "What is the result for the values in question?", "kind": "measurement" } ] } ] } ] }, { "id": "domains", "name": "Domains", "description": "pH by domain.", "rationale": "Application.", "layers": [ { "id": "health", "name": "Health", "description": "Blood and urine pH.", "findings": [ { "id": "health-finding", "name": "Health", "description": "Health.", "questions": [ { "text": "What are normal blood and urine pH ranges, and what do deviations indicate, in general terms?", "kind": "provenance" }, { "text": "Is the user asking about their own test results, which need a clinician?", "kind": "boundary" } ] } ] }, { "id": "environment", "name": "Environment", "description": "Soil, water and materials.", "findings": [ { "id": "environment-finding", "name": "Environment", "description": "Environment.", "questions": [ { "text": "How is pH used in soil management, water quality and paper conservation?", "kind": "provenance" }, { "text": "Which entry fits soil pH?", "kind": "action" } ] } ] } ] }, { "id": "context", "name": "Context", "description": "History and teaching.", "rationale": "Context.", "layers": [ { "id": "history", "name": "History", "description": "History.", "findings": [ { "id": "history-finding", "name": "History", "description": "History.", "questions": [ { "text": "How was pH introduced by Sorensen in 1909, and how has its definition changed?", "kind": "provenance" }, { "text": "Which entry fits the history of chemistry?", "kind": "action" } ] } ] }, { "id": "teach", "name": "Teach", "description": "Teaching.", "findings": [ { "id": "teach-finding", "name": "Teach", "description": "Teaching.", "questions": [ { "text": "How is pH taught, and which misconceptions arise?", "kind": "provenance" }, { "text": "Which sources are cited?", "kind": "provenance" } ] } ] } ] } ] }, "openQuestions": [ "Should blood pH and soil pH be separate entries?", "How should measurement standards be linked?", "The registry entry has merged aliases naming domain-specific values; should they be split off?" ], "statistics": { "bundles": 4, "layers": 8, "findings": 8, "questions": 16 } }, "draft": { "generator": "vr.draft.v3", "status": "draft-generated", "researched": false, "archetype": "abstract concept", "method": "Written from the archetype playbook - what this kind of thing needs beyond identity and provenance - and from the structure that recurred across 6,333 models already researched by two engines. Applied to this entry by rule. No source was read for this thing and no claim here is researched. This entry carries no facets of its own, so they were inferred from its domain - a guess about a whole domain applied to one thing.", "facetsInferred": true, "nextPass": "A researcher replaces this draft with a sourced specification. Treat every sentence below as a proposal to argue with.", "purpose": "Give an agent a durable, checkable way to recognise a pH, record what state it is in, and decide what may be done with it.", "whatItIs": "Let an agent explain pH and its definition, relay measurement methods and standards, describe typical values and their significance in domains such as blood, soil and paper, and route personal health questions to clinicians.", "characteristics": { "substance": "abstract", "origin": "conceptual", "agency": "inert" }, "whatYouCanDoWithIt": [ "observed and measured" ], "distinguishingFeatures": [ "Names folded into this entry, which a task may need to split apart again: pH of Urine, pH value of paper, circumneutral, arterial blood pH, soil pH, pH of blood.", "6 finer distinctions are held as aliases rather than separate entries, because telling them apart needs a task that asks for it.", "Described in 109 Wikipedia languages, which is a measure of how widely the thing is known, not of how important it is." ], "openQuestionsForResearch": [ "Which of the bundles below does a real task actually need, and which are ceremony?", "What does this thing have that the facets do not capture at all?", "Which neighbouring kind is most often confused with a pH, and on what evidence are they told apart?" ], "whatItIsMadeOf": "an abstraction with no physical instance", "physicalCharacter": [ "Does nothing on its own; everything it does, something else did to it.", "These come from the domain this entry sits in rather than from the entry itself, so treat them as a first guess about the whole domain applied to one thing." ], "whatCanBeDoneWithIt": [ "observe it, measure it, record its state" ], "howItIsRecognised": [ "Nothing to see. What is recognised is an instance of it, and which instances count is exactly what is argued about." ], "relatedModels": [ { "relation": "covers", "note": "Finer kinds folded into this entry because telling them apart needs a task that asks for it. Each is a model waiting to be split out when one does.", "targets": [ "pH of Urine", "pH value of paper", "circumneutral", "arterial blood pH", "soil pH", "pH of blood" ] } ], "standing": "Described in 109 Wikipedia languages, which measures how widely it is written about rather than how important or how common it is. 6 finer distinctions are held inside this entry as names rather than as separate models.", "structure": { "bundles": [ { "id": "identity-and-classification", "name": "Identity, naming and classification", "description": "How an agent tells one pH from another, and a pH from things that resemble it.", "rationale": "Recognition comes before every other claim. Without stable identity nothing else in the model can be trusted to be about the same thing twice.", "layers": [ { "id": "naming-and-identifiers", "name": "Names and identifiers", "description": "The names this thing goes by and the identifiers that survive translation and time.", "findings": [ { "id": "preferred-name-and-aliases", "name": "Preferred name, aliases and local names", "description": "Which name to use, which names mean the same thing, and which merely sound similar.", "questions": [ { "id": "preferred-name-and-aliases-q01", "text": "What identifies and describes the name of a pH, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "preferred-name-and-aliases-q02", "text": "Who or what asserted this about the name of a pH, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "preferred-name-and-aliases-q03", "text": "What may an agent decide or do once the name of a pH is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] }, { "id": "stable-identifiers", "name": "Stable identifiers and external keys", "description": "Identifiers that keep pointing at this kind of thing across systems and languages.", "questions": [ { "id": "stable-identifiers-q01", "text": "What identifies and describes an identifier for a pH, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "stable-identifiers-q02", "text": "Who or what asserted this about an identifier for a pH, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "stable-identifiers-q03", "text": "What may an agent decide or do once an identifier for a pH is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] }, { "id": "classification-and-granularity", "name": "Classification and granularity", "description": "Where a pH sits among kinds, and how finely a task needs to cut it.", "findings": [ { "id": "kind-and-parents", "name": "Kind, parents and neighbouring kinds", "description": "The classes this thing belongs to and the ones it is next to.", "questions": [ { "id": "kind-and-parents-q01", "text": "What identifies and describes the kind of a pH, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "kind-and-parents-q02", "text": "Who or what asserted this about the kind of a pH, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "kind-and-parents-q03", "text": "What may an agent decide or do once the kind of a pH is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] }, { "id": "distinguishing-features", "name": "Distinguishing features", "description": "What separates a pH from the things most often confused with it.", "questions": [ { "id": "distinguishing-features-q01", "text": "What identifies and describes what distinguishes a pH, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "distinguishing-features-q02", "text": "Who or what asserted this about what distinguishes a pH, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "distinguishing-features-q03", "text": "What may an agent decide or do once what distinguishes a pH is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] } ] }, { "id": "state-and-lifecycle", "name": "State and lifecycle", "description": "The states a pH passes through and the events that move it between them.", "rationale": "Most decisions about a thing depend on what state it is in now, which is a claim with a time on it, not a property.", "layers": [ { "id": "lifecycle-stages", "name": "Lifecycle stages", "description": "From coming into existence to ceasing to be one of these.", "findings": [ { "id": "stages-and-transitions", "name": "Stages and transitions", "description": "The stages worth naming and what moves a pH between them.", "questions": [ { "id": "stages-and-transitions-q01", "text": "What identifies and describes the lifecycle of a pH, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "stages-and-transitions-q02", "text": "Who or what asserted this about the lifecycle of a pH, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "stages-and-transitions-q03", "text": "What may an agent decide or do once the lifecycle of a pH is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] }, { "id": "observations-and-status", "name": "Observations and current status", "description": "What is observed about a pH, how often and by whom.", "findings": [ { "id": "observation-record", "name": "Observation record", "description": "How an observation of a pH is recorded so that it can be superseded rather than overwritten.", "questions": [ { "id": "observation-record-q01", "text": "What identifies and describes an observation of a pH, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "observation-record-q02", "text": "Who or what asserted this about an observation of a pH, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "observation-record-q03", "text": "What may an agent decide or do once an observation of a pH is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] } ] }, { "id": "definitions-in-contest", "name": "Definitions and who holds them", "description": "What pH is taken to mean, and by whom.", "rationale": "When a field disagrees about a concept, the disagreement is the content. A model that picks one definition silently destroys the information.", "layers": [ { "id": "competing-definitions", "name": "Competing definitions", "description": "The main readings and the traditions behind them.", "findings": [ { "id": "definition-map", "name": "Definitions and their holders", "description": "Each definition with the school or body that holds it.", "questions": [ { "id": "definition-map-q01", "text": "Which definitions of pH are in use, and which tradition or body holds each?", "kind": "definition" }, { "id": "definition-map-q02", "text": "What turns on the difference between them in practice?", "kind": "boundary" } ] } ] }, { "id": "operationalisation", "name": "Operationalisation", "description": "How it is measured or applied when it has to be.", "findings": [ { "id": "operational-record", "name": "Measures and proxies", "description": "Instruments and indicators used to stand in for it.", "questions": [ { "id": "operational-record-q01", "text": "How is pH operationalised or measured in practice, and by what instrument?", "kind": "measurement" }, { "id": "operational-record-q02", "text": "What does that operationalisation leave out, and when does that matter?", "kind": "boundary" } ] } ] } ] }, { "id": "instances-and-use", "name": "Instances, use and consequence", "description": "What counts as an instance of pH and what follows from calling something that.", "rationale": "Applying a concept is an act with consequences, so a model must say what the label licenses and what it does not.", "layers": [ { "id": "instances", "name": "What counts as an instance", "description": "Clear cases, borderline cases and non-cases.", "findings": [ { "id": "instance-tests", "name": "Tests for an instance", "description": "What would settle whether something falls under it.", "questions": [ { "id": "instance-tests-q01", "text": "What would settle whether something is an instance of pH?", "kind": "boundary" }, { "id": "instance-tests-q02", "text": "Which borderline cases are argued about, and on what grounds?", "kind": "definition" } ] } ] }, { "id": "consequence", "name": "Consequence of application", "description": "Rights, duties or decisions that follow from the label.", "findings": [ { "id": "consequence-record", "name": "What the label licenses", "description": "What an agent may do once something is classified this way.", "questions": [ { "id": "consequence-record-q01", "text": "What follows practically once something is treated as pH?", "kind": "action" }, { "id": "consequence-record-q02", "text": "What must an agent not infer from the label alone?", "kind": "action" } ] } ] } ] }, { "id": "provenance-and-evidence", "name": "Provenance, evidence and time", "description": "Where every claim about a pH came from and when it held.", "rationale": "A claim without a source and a time cannot be superseded, only overwritten, and an agent that overwrites loses the ability to explain itself.", "layers": [ { "id": "source-and-authority", "name": "Source and authority", "description": "Who said it, on what evidence, and how strongly.", "findings": [ { "id": "claim-provenance", "name": "Claim provenance and confidence", "description": "The authority behind each claim about a pH and how confident it is.", "questions": [ { "id": "claim-provenance-q01", "text": "What identifies and describes a claim about a pH, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "claim-provenance-q02", "text": "Who or what asserted this about a claim about a pH, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "claim-provenance-q03", "text": "What may an agent decide or do once a claim about a pH is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] }, { "id": "time-and-versions", "name": "Time, versions and supersession", "description": "When a claim was true, when it was learnt, and what replaced it.", "findings": [ { "id": "validity-and-supersession", "name": "Validity period and supersession", "description": "How an old claim about a pH is retired without being erased.", "questions": [ { "id": "validity-and-supersession-q01", "text": "What identifies and describes the validity of a claim about a pH, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "validity-and-supersession-q02", "text": "Who or what asserted this about the validity of a claim about a pH, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "validity-and-supersession-q03", "text": "What may an agent decide or do once the validity of a claim about a pH is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] } ] } ] }, "statistics": { "bundles": 5, "layers": 10, "findings": 12, "questions": 32 } } } }