cup
Let an agent convert and interpret cup measures by naming the system, and never assume one cup is the same everywhere.
Bundle → Layer → Finding → Questions Filled
4 bundles · 8 layers · 8 findings · 16 questions
System and size Which cup is meant.
System
US, metric, imperial or Japanese.
Cup system
The system assumed by the source.
- Which cup system does this source use? provenance
- What evidence in the source indicates it? provenance
Size
Exact volume.
Exact volume
The volume in millilitres.
- What is the exact volume of this cup in millilitres? measurement
- What rounding is acceptable for this use? boundary
Conversion To other units.
Volume conversion
To millilitres and spoons.
Volume factors
Factors to other volume units.
- How many millilitres, tablespoons or teaspoons is this? measurement
- Are the spoons in the same system? boundary
Mass conversion
To grams by ingredient.
Density used
The ingredient density used.
- What density was used to convert to grams? provenance
- How much does packing or sifting change it? boundary
Measuring practice How people measure.
Technique
Levelling, packing and spooning.
Technique used
How the cup is filled.
- How should the cup be filled for this ingredient? action
- How much variation does technique introduce? measurement
Tools
Measuring cups and jugs.
Tool calibration
The measuring tool and its markings.
- Which measuring tool is used, and in which system is it marked? definition
- How accurate is it? measurement
Safety and labelling Where accuracy matters.
Nutrition labelling
Serving sizes.
Labelling rule
The legal cup used on labels.
- Which cup definition applies to this label? provenance
- How does it compare with the household cup? measurement
Medicine
Why not to use cups for doses.
Dosing guidance
Guidance against household measures for medicine.
- Is a cup measure being used for a medicine dose? boundary
- What should be used instead? action
Classifiers Filled
- Family
- Thing Registry
- Category
- Cross-cutting context
- Entry kind
- thing
- Plane
- XCT
- Domain
- XCT.QTY
What it is Filled
A unit of volume used mainly in cooking, whose size depends on the system: the US customary cup of about 236.6 ml, the US legal cup of 240 ml, the metric cup of 250 ml, and others.
Why it exists Filled
Let an agent convert and interpret cup measures by naming the system, and never assume one cup is the same everywhere.
Distinguishing features Filled
- A volume unit, not a mass unit
- Varies by country and use, so the system must be stated
- Not part of the SI
- Different from the drinking cup, the object
What robots and AI may and may not do Filled
Must not
- Assume one cup size when the recipe's system is unknown.
- Convert cups to mass without the ingredient's density.
- Advise measuring medicine with kitchen cups.
Only with a human decision
- Converting measures for medical or infant feeding.
May
- Convert cup measures once the cup system is known.
- Scale recipes and state the cup system used.
Moral aspects Filled
- Measurement errors in food can harm people with medical diets or allergies.
Who is affected
- Cooks and bakers
- People on medical diets
Owners Filled
Steward
Nobody owns it; national standards bodies define customary and metric units.
Links to other meta-models Filled
parent
- Q1302471 - registry parent class
- Q16782623 - registry parent class
related
- unit of volume - converts to the SI litre
- cup as a vessel - a homonym; the vessel is an object
- density - mass equivalents depend on the ingredient
- recipe - the main context
What else AI and robots need to interact with it Filled
Identity and identifiers required Filled
- Vercy registry: vr.tr.cup-q1242244
- Wikidata: Q1242244 (https://www.wikidata.org/wiki/Q1242244)
- UCUM unit code: [cup_us], [cup_m] Unified Code for Units of Measure
Direct properties not applicable Not applicable
- US customary cup: 236.588 ml - half a US liquid pint
- US legal cup: 240 ml - used for nutrition labelling
- metric cup: 250 ml - Australia, Canada, New Zealand and others
- Japanese cup: 200 ml - rice cup is about 180 ml
Plane XCT: no invented physical properties.
Recognition optional Filled
- Measuring cups marked with fractions of a cup
- Recipe text using "cup" or "c."
- The drinking cup is not a measure; this entry is the unit
- A graduated measuring cup or a set of nested cups marked 1, 1/2, 1/3 and 1/4.
Capabilities and actions required Filled
- measure ingredients, with a measuring cup
- convert it to millilitres, once the system is known
- convert it to mass, only with the density of the ingredient
- scale a recipe
Hazards and failure modes required Filled
- Using the wrong cup size, which changes a recipe by several percent
- Converting cups to grams without the ingredient density
- Dosing medicine with kitchen cups instead of calibrated measures
Standards and interfaces required Filled
- US FDA nutrition labelling rules defining the 240 ml cup
- NIST Handbook 44 for US customary units
- UCUM for coded units
Context of use required Filled
- Measuring ingredients by volume in recipes.
- US customary cup
- US legal cup
- metric cup
- imperial cup
- Japanese cup and rice cup
Sources Filled
- Wikidata item Q1242244: cup - identity and sense of the item
- Wikipedia: Cup (unit) - general description of the item
Open questions
- Should each cup system be a separate unit entry?
- How should recipes record which cup they assume?
- Should the registry hold density tables for common ingredients?
Machine files
Provenance
thing registry research (pass 2) · unreviewed
Built from: models/things/publications/thing-q1242244/spec.json