{ "model": { "rank": 9646, "code": "thing-q208469", "model_id": "vr.tr.si-derived-unit", "name": "SI derived unit", "purpose": "Let an agent explain SI derived units and their construction, relay the units with special names, coherence and dimensionless units from the SI Brochure, describe their use, and distinguish derived units from base units, non-SI units accepted for use and prefixed units.", "family": "Thing Registry", "category": "Cross-cutting context", "status": "research-draft", "kind": "thing", "plane": "XCT", "domain": "XCT.QLT", "industry": "", "version": "", "url": "/models/thing/q208469/", "tier": 2, "score": 47, "payload": { "layer": "wikidata", "aliases": [ "SI dimensionless derived unit", "unit of reciprocal amount-of-substance", "SI unit with special name", "coherent SI unit", "unit of ratios of length" ], "aliasCount": 5, "merged": 5, "knownIn": 47, "facets": null, "markers": [], "lexicalClass": "", "senseRank": null, "alsoRegisteredAs": null, "source": { "dataset": "wikidata", "item": "Q208469", "url": "https://www.wikidata.org/wiki/Q208469", "license": "CC0 1.0" } }, "research": { "vercy": "1.0-draft", "publication": { "status": "research-draft", "adjudicationStatus": "unreviewed", "publishableCanonical": false, "generatedAt": "2026-09-13T14:03:52Z", "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": 4, "engine": "claude" }, "metaModel": { "id": "THING-Q208469", "registryId": "vr.tr.si-derived-unit", "name": "SI derived unit", "version": "0.2.0-wave.4", "entryKind": "thing", "family": "Thing Registry", "domain": [ "XCT.QLT" ], "status": "research-draft" }, "canonicalUrl": "https://ver.cy/models/thing/q208469/", "model": { "registry_id": "vr.tr.si-derived-unit", "name": "SI derived unit", "purpose": "Let an agent explain SI derived units and their construction, relay the units with special names, coherence and dimensionless units from the SI Brochure, describe their use, and distinguish derived units from base units, non-SI units accepted for use and prefixed units.", "definition": "A unit of measurement in the International System of Units formed by combining base units, such as the newton, pascal, joule and watt among the 22 coherent derived units with special names, together with derived units expressed only in base units and dimensionless derived units such as the radian and units of ratios of length; derived units are coherent when formed from base units without numerical factors.", "what_it_is_for": "Expressing derived quantities in SI.", "affordances": [ "explain construction", "relay named and dimensionless units", "describe use", "distinguish related units" ], "distinguishing_features": [ "Built from base units", "Coherent", "Special names", "Dimensionless members" ], "appearance": "Not a visible object; unit symbols such as N, Pa, J and W.", "visual_identification": [ "SI unit built from base units", "Newton, pascal, joule, watt, radian, steradian, per mole, ratios of length", "Base units are the seven defined units; accepted non-SI units such as the litre are outside; prefixes scale units" ], "physical_properties": [ { "quantity": "SI base units", "typical_range": "7", "unit": "count", "note": "" }, { "quantity": "derived units with special names", "typical_range": "22", "unit": "count", "note": "" }, { "quantity": "SI Brochure edition", "typical_range": "9th, 2019", "unit": "note", "note": "" } ], "families_and_kinds": [ "coherent derived units with special names such as newton, pascal, joule and watt", "derived units expressed in base units such as metre per second", "dimensionless derived units such as radian and steradian", "units of reciprocal amount of substance such as per mole", "units of ratios of length such as metre per metre" ], "related_models": [ { "relation": "is a kind of", "target": "SI unit", "why": "in registry terms" }, { "relation": "is a kind of", "target": "derived unit", "why": "in registry terms" }, { "relation": "is built from", "target": "SI base unit", "why": "by multiplication and division" }, { "relation": "is exemplified by", "target": "newton", "why": "the unit of force" } ], "identifiers": [ { "scheme": "BIPM", "value_or_pattern": "SI Brochure chapter 2", "note": "derived units" } ], "standards_and_regulation": [ "SI Brochure of the BIPM", "ISO 80000 quantities and units", "National metrology regulations" ], "failure_modes_and_hazards": [ "Confusing derived with base units", "Misusing non-coherent units", "Registry aliases naming unit categories rather than units" ], "in_scope": [], "out_of_scope": [], "characteristics": [] }, "sources": [], "structure": { "bundles": [ { "id": "understand", "name": "Understand", "description": "What SI derived units are.", "rationale": "Science.", "layers": [ { "id": "definition", "name": "Definition", "description": "Definition.", "findings": [ { "id": "definition-finding", "name": "Definition", "description": "Definition.", "questions": [ { "text": "What is an SI derived unit, and how does it differ from base units, accepted non-SI units and prefixed units?", "kind": "definition" }, { "text": "Is the question about the category, a specific unit or a conversion?", "kind": "boundary" } ] } ] }, { "id": "named", "name": "Named", "description": "Named units.", "findings": [ { "id": "named-finding", "name": "Named", "description": "Named.", "questions": [ { "text": "What are the 22 derived units with special names, and what quantities do they measure?", "kind": "definition" }, { "text": "Which entry fits the specific unit?", "kind": "action" } ] } ] } ] }, { "id": "theory", "name": "Theory", "description": "Coherence and dimension.", "rationale": "Science.", "layers": [ { "id": "coherence", "name": "Coherence", "description": "Coherence.", "findings": [ { "id": "coherence-finding", "name": "Coherence", "description": "Coherence.", "questions": [ { "text": "What does coherence mean, and why does it matter in calculations?", "kind": "provenance" }, { "text": "Which references are standard?", "kind": "provenance" } ] } ] }, { "id": "dimensionless", "name": "Dimensionless", "description": "Dimensionless units.", "findings": [ { "id": "dimensionless-finding", "name": "Dimensionless", "description": "Dimensionless.", "questions": [ { "text": "How are the radian, steradian and ratio units treated in the SI?", "kind": "provenance" }, { "text": "Which sources are cited?", "kind": "provenance" } ] } ] } ] }, { "id": "use", "name": "Use", "description": "Use.", "rationale": "Practice.", "layers": [ { "id": "writing", "name": "Writing", "description": "Writing units.", "findings": [ { "id": "writing-finding", "name": "Writing", "description": "Writing.", "questions": [ { "text": "How are derived units written, combined and prefixed correctly?", "kind": "action" }, { "text": "Which entry fits SI unit symbols?", "kind": "action" } ] } ] }, { "id": "conversion", "name": "Conversion", "description": "Conversion.", "findings": [ { "id": "conversion-finding", "name": "Conversion", "description": "Conversion.", "questions": [ { "text": "How are derived units converted from other systems?", "kind": "action" }, { "text": "Which entry fits unit conversion?", "kind": "action" } ] } ] } ] }, { "id": "context", "name": "Context", "description": "History.", "rationale": "Context.", "layers": [ { "id": "history", "name": "History", "description": "History.", "findings": [ { "id": "history-finding", "name": "History", "description": "History.", "questions": [ { "text": "How did the SI derived units develop, and what changed in the 2019 redefinition?", "kind": "provenance" }, { "text": "Which entry fits the 2019 redefinition of the SI base units?", "kind": "action" } ] } ] }, { "id": "bodies", "name": "Bodies", "description": "Governing bodies.", "findings": [ { "id": "bodies-finding", "name": "Bodies", "description": "Bodies.", "questions": [ { "text": "What roles do the BIPM, CGPM and national institutes play?", "kind": "provenance" }, { "text": "Which entry fits International Bureau of Weights and Measures?", "kind": "action" } ] } ] } ] } ] }, "openQuestions": [ "Should the 22 named units be linked individually?", "How should the SI Brochure be linked?", "The registry entry has merged aliases naming categories of derived units; 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": "unit, quantity or measure", "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 SI derived unit, record what state it is in, and decide what may be done with it.", "whatItIs": "Let an agent explain SI derived units and their construction, relay the units with special names, coherence and dimensionless units from the SI Brochure, describe their use, and distinguish derived units from base units, non-SI units accepted for use and prefixed units.", "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: SI dimensionless derived unit, unit of reciprocal amount-of-substance, SI unit with special name, coherent SI unit, unit of ratios of length.", "5 finer distinctions are held as aliases rather than separate entries, because telling them apart needs a task that asks for it.", "Described in 47 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 SI derived unit, 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: a unit is a convention. What is seen is an instrument reading in it." ], "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": [ "SI dimensionless derived unit", "unit of reciprocal amount-of-substance", "SI unit with special name", "coherent SI unit", "unit of ratios of length" ] } ], "standing": "Described in 47 Wikipedia languages, which measures how widely it is written about rather than how important or how common it is. 5 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 SI derived unit from another, and a SI derived unit 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 SI derived unit, 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 SI derived unit, 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 SI derived unit 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 SI derived unit, 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 SI derived unit, 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 SI derived unit 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 SI derived unit 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 SI derived unit, 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 SI derived unit, 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 SI derived unit 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 SI derived unit from the things most often confused with it.", "questions": [ { "id": "distinguishing-features-q01", "text": "What identifies and describes what distinguishes a SI derived unit, 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 SI derived unit, 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 SI derived unit 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 SI derived unit 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 SI derived unit between them.", "questions": [ { "id": "stages-and-transitions-q01", "text": "What identifies and describes the lifecycle of a SI derived unit, 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 SI derived unit, 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 SI derived unit 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 SI derived unit, how often and by whom.", "findings": [ { "id": "observation-record", "name": "Observation record", "description": "How an observation of a SI derived unit 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 SI derived unit, 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 SI derived unit, 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 SI derived unit is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] } ] }, { "id": "definition-and-realisation", "name": "Definition, dimension and realisation", "description": "What SI derived unit is defined as and how it is realised in practice.", "rationale": "A unit is not the quantity it measures, and its definition has a history that older data still depends on.", "layers": [ { "id": "definition", "name": "Definition and dimension", "description": "The defining relation and the quantity it measures.", "findings": [ { "id": "definition-record", "name": "Definition, body and date", "description": "What defines it now, and what defined it before.", "questions": [ { "id": "definition-record-q01", "text": "How is SI derived unit defined, by which body, and since when?", "kind": "definition" }, { "id": "definition-record-q02", "text": "What was the previous definition, and what data still depends on it?", "kind": "provenance" } ] } ] }, { "id": "conversion", "name": "Conversion and compatibility", "description": "Relations to other units, exact or approximate.", "findings": [ { "id": "conversion-record", "name": "Conversions and their exactness", "description": "Factors, and whether each is exact by definition.", "questions": [ { "id": "conversion-record-q01", "text": "What conversions relate SI derived unit to other units, and which are exact by definition?", "kind": "measurement" }, { "id": "conversion-record-q02", "text": "Where does rounding a conversion change a decision, and how should that be recorded?", "kind": "action" } ] } ] } ] }, { "id": "provenance-and-evidence", "name": "Provenance, evidence and time", "description": "Where every claim about a SI derived unit 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 SI derived unit and how confident it is.", "questions": [ { "id": "claim-provenance-q01", "text": "What identifies and describes a claim about a SI derived unit, 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 SI derived unit, 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 SI derived unit 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 SI derived unit is retired without being erased.", "questions": [ { "id": "validity-and-supersession-q01", "text": "What identifies and describes the validity of a claim about a SI derived unit, 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 SI derived unit, 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 SI derived unit is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] } ] } ] }, "statistics": { "bundles": 4, "layers": 8, "findings": 10, "questions": 28 } } } }