National Gallery of Art Open Data Program: Collection Data in CSV Format Introduction Thank you for your interest in data about the National Gallery of Art’s collection. The comma separated value files contained on this GitHub site represent a cross-section of public, fact-based data about our collection. They contain an export of data about the NGA’s accessioned art objects, relationships between those art objects, the creators of those objects, donors who helped the NGA acquire the objects, the object’s provenance, and the public locations where the collection can be viewed, as well as links to access audio and video about the collection and people and images depicting the works. The NGA is releasing these files under the Creative Commons Zero (CC0) designation. You are free to use the data in any manner consistent with the CC0 designation. Please note that while links to media files and images contained in this data are being released under a CC0 designation, the content of the linked sites might still be copyrighted. The NGA’s Open Access Policy, for example, applies to only a subset of the images that are linked in this dataset. The full dataset is updated frequently (usually once a day), and the date of a particular CSV file can be confirmed by examining the last commit date reported by GitHub. We appreciate your feedback and questions about the NGA’s open data program and are interested in learning about all the innovative ways that people are using our data, so please let us know! The remainder of this document describes the data elements comprising the CSV formatted open dataset. About Objects and Constituents: Art Objects comprise collections and are therefore one of two typical starting points for exploring a collection. The Object Identifier, a.k.a., “objectID” is a unique sequential identifier assigned by the CMS system to each new art object registered in the collection management system. The objectID is used to link many tables with the objects table which is the core table of the collection. Another equally important table is the constituents table. Similarly, a constituentID is assigned by the CMS whenever a new party is defined in the system. The relationship table “objects_constituents” holds important metadata about the relationships between art objects and constituents and includes several types of relationships such as art object creator and donor. Composite Art Objects: The structure of art objects can be somewhat complex. While many objects are comprised of a single physical part, other objects are comprised of multiple parts, with either a conceptual relationship or a physical relationship, that together make up the full cataloguing of the object. An object like a triptych with 3 separate panels, might have 3 individual records to describe each panel, but then another record to describe the triptych as a whole. Each panel would be related to this record as a part of the whole, but function as a separate object as well. In the case of multiple objects records that are physically part of a single object from which they cannot be separated, like a medal or pages in a bound volume, these records would be connected with an inseparable intellectual child relationship. The child record(s) do not function independently from the physical parent record. It is the decision of the collection management specialist to decide how best to model art objects using the various options available in the collection management system. This document focuses primarily on a deeper description of composite objects, i.e. objects comprised of two or more art objects. Art Object Modeling Terms: Inseparable Intellectual Object A single physical object with multiple intellectual parts, e.g. a coin where each side has been cataloged separately as a logical object or a book where all the pages are bound together. These objects cannot be physically separated from one another. One part is designated the “Parent” object, and then any additional parts would be designated inseparable Intellectual Objects. In the case of an object with drawings on both sides (recto/verso), the primary image (recto) would be designated the parent and then the secondary side (verso) would be related as an inseparable intellectual child record. Separable Object An object composed of multiple, separable parts, e.g. a painting that spans three panels or a sculpture consisting of two physical parts. Cover Record An object record that represents a set of related physical or intellectual objects, e.g. the overall book of etchings where each page is cataloged as a separate object, an inseparable intellectual child object, or a record describing the entire portfolio or series of prints, where each print is related as a separable object, or a record that describes an entire altarpiece, where each panel is related as a separable object. Virtual Object An object that does not itself constitute a physical collection object, e.g. a portfolio of etchings, where there is no physical container –the cover record describes the portfolio of prints as a whole, or a case where a cover record was created for a diptych – the record describes the diptych as a whole, and the two parts are related as separable objects, however the cover record does not constitute a 3rd physical object. e.g. the cover of a book with etchings inside, a box of loose-leaf drawings, etc.   This status is recorded in the column isVirtual in the objects table.  There are currently no cases of virtual child objects. Physical Object An object that, in its physical entirety, is a work of art, and can function independently and separately from another object.   Physical Object Parent The parent object record of an intellectual child object in an inseparable relationship, e.g. head side of a coin.   Inseparable (intellectual) objects have a Physical Parent ID.  Separable (physical) objects, with which inseparable objects may be associated, do not have a Physical Parent ID (presumably because they are physical objects themselves and so do not need this distinction). The status of virtual on an object has nothing to do with physical parent object. Inter-Object Relationships: Direct structural relationships between art objects are contained in the table associations. When objects are related to one another, they are linked through parent-child relationships and the relationship is characterized as being either physically separable or inseparable. Examples: Inseparable coins, one physical object as recto parent: http://www.nga.gov/content/ngaweb/Collection/art-object-page.139898.html Inseparable print, one physical object as recto parent:  http://www.nga.gov/content/ngaweb/Collection/art-object-page.67361.html Inseparable drawing with cover record, e.g. http://www.nga.gov/content/ngaweb/Collection/art-object-page.125203.html Inseparable portfolio with physical cover record parent, e.g. http://www.nga.gov/content/ngaweb/Collection/art-object-page.76219.html Inseparable drawing with cover record as parent, e.g. http://www.nga.gov/content/ngaweb/Collection/art-object-page.143762.html Inseparable two sided painting, physical parent (same situation as coins), e.g. http://www.nga.gov/content/ngaweb/Collection/art-object-page.50724.html Inseparable decorative art (four pieces) with one physical object chosen as parent: http://www.nga.gov/content/ngaweb/Collection/art-object-page.52354.html Separable decorative art with two pieces and one of them is physical parent: http://www.nga.gov/content/ngaweb/Collection/art-object-page.53152.html  Separable panels with one panel as physical parent: http://www.nga.gov/content/ngaweb/Collection/art-object-page.2.html - left panel is parent Separable panels currently not associated with each other: http://www.nga.gov/content/ngaweb/Collection/art-object-page.282.html and http://www.nga.gov/content/ngaweb/Collection/art-object-page.10.html Separable panels with one virtual cover record parent: http://www.nga.gov/content/ngaweb/Collection/art-object-page.111637.html Separable portfolio with virtual cover record parent: http://www.nga.gov/content/ngaweb/Collection/art-object-page.71729.html - parent should probably be virtual but is marked as physical Separable portfolio with physical cover record parent: http://www.nga.gov/content/ngaweb/Collection/art-object-page.95381.html - example where cover can be considered a work itself Separable portfolio with virtual cover record parent: http://www.nga.gov/content/ngaweb/Collection/art-object-page.163596.html Separable drawing with virtual cover record parent: http://www.nga.gov/content/ngaweb/Collection/art-object-page.141579.html Separable sculpture with physical cover record parent: http://www.nga.gov/content/ngaweb/Collection/art-object-page.130750.html - each side cataloged as separate object Separable volume with physical cover record parent: http://www.nga.gov/content/ngaweb/Collection/art-object-page.58003.html Data Dictionary: Detailed descriptions of the data files and their elements: This data dictionary contains the SQL required to define your own working database in PostGreSQL should you choose to load and query the data using a RDBMS. Table, Column, and Type Description CREATE TABLE alternative_identifiers Alternative identifiers for NGA objects and constituents. ( uuid character varying (64) NOT NULL, universally unique identifier for an instance of an NGA entity, e.g. an art object, image, artist, etc. idschemelabel character varying (64) NOT NULL, key name for the identification scheme to which identifier belongs, e.g. a “Wikidata ID” identifier character varying (64) NOT NULL The value of the identifier ) CREATE TABLE constituents A constituent is a single person or a group of persons (see constituent type). Constituents in the extract typically have a relationship with one or more objects in the public objects extract. Relationships are defined in another table, but a constituent may be an artist, an owner, or a donor, or all of these. we only use a limited number of anonymous artists to represent all anonymous artists of works it is possible for some fields, e.g. biography, to have embedded HTML italics tags – this is generally true of about a dozen columns across various tables in the public collection extract – in some cases underscores are used and in other cases simple HTML markup is present ( constituentID integer NOT NULL PRIMARY KEY, primary key (tms identifier) uuid nvarchar(36) NULL, a persistent unique identifier for this constituent; used as a key into other tables such as alternative numbers and will play a more active role in linking constituents with other data sources moving forward ULANID character varying(32) NULL, Getty ULAN ID - partially applied to NGA artists - not all artists are in ULAN and not all matches have been curated yet preferredDisplayName character varying(256) NULL, inverted full name of the constituent - this is the NGA's preferred name for the constituent forwardDisplayName character varying(256) NULL, forward direction preferred full name of the constituent lastName character varying(256) NULL, preferred last name of the constituent displayDate character varying(256) NULL, birth and death dates in human readable form artistOfNGAObject integer NOT NULL, 0 = not an artist associated with an NGA accessioned object 1 = artist of an NGA accessioned object beginYear integer NULL, birth year endYear integer NULL, death year visualBrowserTimeSpan character varying(32) NULL, computed time-span slot for this artist's life nationality character varying(128) NULL, nationality of the artist - not all values are conforming visualBrowserNationality character varying(128) NULL, one of the top 25 normalized nationalities or "other" if outside of top 25 constituentType character varying(30) NOT NULL, anonymous corporate couple individual purchase_fund wikidataid character varying(64) NULL Wikidata ID – partially applied to NGA artists – not all artists in represented in Wikidata. ) CREATE TABLE constituents_altnames Alternative names used by or assigned to constituents for various purposes as indicated by the nametype column. Curators might prefer to use one name whereas the constituent might be referred to by in other publications or sources by a different name. ( altnameid integer NOT NULL PRIMARY KEY, primary key constituentid integer NOT NULL, foreign key to constituents table lastname character varying(256), alternate last name displayname character varying(256), alternate display name forwarddisplayname character varying(256), alternate display name forwards direction (first name followed by last name) nametype character varying(32) NOT NULL, type of alternate name; one of: Birth Name Full Name Maiden Name Married Name Nickname/Pseudonym Original Name Preferred Name Spouse Unicode Display Name Variant Variant Index Name ); CREATE TABLE constituents_text_entries stores long texts associated with constituents ( constituentID integer NOT NULL, foreign key to constituents table text character varying NOT NULL, the text itself which may or may not contain one of several embedded formatting adornments textType character varying(32) NOT NULL, currently only contains "bibliography" year character varying(4) NULL, the year the text was published ) CREATE TABLE locations The location represents the physical public location of an art object within the confines of the National Gallery of Art’s Washington, D.C. campus. Note: when the gallery is partially or fully closed for an extended period, such as an infrastructure project or the COVID-19 pandemic, some locations might not be listed if they are currently closed to the public. Note that object locations are defined at the unitPostion level (N, S, E, W, etc.), so each wall in each room has a different location ID – this means the description of the location might be duplicated multiple times for different location IDs. ( locationID integer NOT NULL PRIMARY KEY, foreign key to locations table site character varying(64) NOT NULL, currently either "East Building" or "West Building”, the two primary sites of the NGA - Sculpture Garden is considered as West Building . room character varying(64) NOT NULL, the room within the site, e.g. G-132 publicAccess integer NOT NULL, 0 = no public access 1 = public access only public access locations are included in the files. description character varying(256) NOT NULL, full text description of the location, e.g. East Bldg, Mezz Gal 214B (Pod 2) unitPosition character varying(64) NULL, location within the room, e.g. SOUTH LEDGE ) CREATE TABLE media_items a table containing audio and video items published to www.nga.gov ( mediaID bigint NOT NULL PRIMARY KEY, numerical identifier for externally managed media - BrightCove and SoundCloud are our media providers and they both use large integers for media identifiers mediaType varchar(32) NOT NULL, audio or video title varchar(2048) NULL, title of the media item description text NULL, HTML fragment description of the media item duration int NULL, duration of the media item in seconds (there could be manually entered errors in some of these values) language varchar(12) NOT NULL, two letter language without localization, e.g. en, fr, zh thumbnailURL varchar(1024) NULL, full URL to the thumbnail playURL varchar(1024) NULL, a URL that can be used to play the media file directly downloadURL varchar(1024) NULL, a URL that allegedly can be used to download the media file directly (no option for brightcove so many nulls) keywords varchar(2048) NULL, a list of non-vocabulary-controlled keywords assigned to the media item internally tags varchar(2048) NULL, a list of AEM tags assigned to the media item by authors imageURL varchar(1024) NULL, similar to thumbnail, but for a full-size image presentationDate timestamp with time zone NULL, the presentation date of an event represented by this media releaseDate timestamp with time zone NULL, publication date lastModified timestamp with time zone NULL, last modification date of the media item ) CREATE TABLE media_relationships records relationships between media items and core NGA art entities ( mediaID bigint NOT NULL, foreign key to media items table relatedID bigint NOT NULL, foreign key into the relevant table for the relatedEntity relatedEntity varchar(32) NOT NULL, the related entity, currently either nga:art:tms:constituents or nga:art:tms:objects PRIMARY KEY(mediaID, relatedID, relatedEntity) the composite primary key for this table ) CREATE TABLE object_associations relationships between art objects - see accompanying documentation about types of art objects and relationships between them ( parentObjectID integer NOT NULL, the object ID of this object's parent if it has one; foreign key into objects table childObjectID integer NOT NULL, the object ID of this object's child if is has any; foreign key into objects table relationship character varying(32) NOT NULL, inseparable or separable - refers to the physical separability of the two objects PRIMARY KEY(parentObjectID, childObjectID, relationship) the composite primary key for this table ) CREATE TABLE objects_altnums relationships between art objects - see accompanying documentation about types of art objects and relationships between them ( objectid integer NOT NULL, foreign key to the objects table altnumtype character varying(64) NOT NULL, type of alternative number, e.g. Stieglitz Estate Number altnum character varying(64) NOT NULL, the alternative number itself ) CREATE TABLE objects_constituents One of the most important elements of the extract, the object / constituent relationships describe the association between a constituent and an object. ( objectID integer NOT NULL, foreign key to the objects table constituentID integer NOT NULL, foreign key to the constituents table displayOrder integer NOT NULL, order in which to display the list of constituent relationships for a given object roleType character varying(64) NOT NULL, currently includes "artist", "donor", and "owner" role types role character varying(64) NOT NULL, for each role type, there are specific roles, e.g. for artist, one of the roles is "painter" prefix character varying(64) NULL, text prefix associated with the relationship / transaction suffix character varying(64) NULL, text suffix associated with the relationship / transaction displayDate character varying(128) NULL, human readable date(s) associated with the relationship / transaction beginYear integer NULL, four digit year when the relationship / transaction started endYear integer NULL, four digit year when the relationship / transaction ended country character varying(64) NULL, the full country name where the relationship / transaction occurred zipCode character varying(16) NULL, the postal code where the relationship / transaction occurred ) CREATE TABLE objects_dimensions records various dimensions for objects ( objectID integer NOT NULL, foreign key to the objects table element character varying(32) NOT NULL, a qualifier for the object element to which the dimension applies - does not yet conform to a controlled vocabulary dimensionType character varying(32) NOT NULL, the type of measurement, e.g. width, height, diameter dimension decimal(22,10) NOT NULL, the numerical measurement itself, e.g. 21.22 unitName character varying(32) NOT NULL, the units of the measurement, e.g. centimeters, grams, pounds, etc. ) CREATE TABLE objects_historical_data records a very light audit trail for certain important object properties ( dataType character varying(32) NOT NULL, currently either "previous_attribution" or "previous_title" objectID integer NOT NULL, foreign key to the objects table displayOrder integer NOT NULL, the preferred order in which to display the historical values for a given object and data type forwardText character varying NULL, the historical attribution record value, forward facing invertedText character varying NULL, the historical attribution record value, inverted remarks character varying NULL, remarks associated with the record effectiveDate character varying(10) NULL, a human readable date associated with the record ) CREATE TABLE objects Art objects are a core entity of the collection extract. Objects are physical or logical constructs and all but a very small number of them in this extract are NGA objects with accession numbers. Imagery for an object should not be displayed unless the canShowImagery flag is 1 If an image copyright exists, it must always be displayed with each image of the object There can be multiple images per object The begin and end dates are provided to facilitate returning the object via search, but they are no foolproof.  For example, when the displayDate is unset, usually the begin and end dates are the artist’s life dates since that’s the best information available. Underscores appearing in nvarchar columns should be treated as an italicizing markup, e.g., _title_ => title ( objectID integer NOT NULL PRIMARY KEY, the primary identifier for an art object - identifier is created by the NGA's collection management system (tms); primary key for the table uuid nvarchar(36) NULL, a persistent unique identifier for this art object; used as a key into other tables such as alternative numbers and will play a more active role in linking the art object with other data sources moving forward accessioned integer NOT NULL, 0 | 1 flag indicating whether this object is an NGA accessioned work - for the public collection extract, this should always be 1 accessionNum character varying(32) NULL, accession number assigned to an art object - art objects that are not accessioned works do not begin with a year - otherwise, the vast majority of NGA art object accession numbers are formatted with a numbering system starting with the year, then followed by an accession lot, and finally ordering within that lot, e.g. 1942.2.1 - depending on the complexity of an art object these can be more complicated objectLeonardoID character varying(16) NULL, prior legacy CMS sytem id - might consider moving these to the historical_data table or the object_altnums table locationID integer NULL, location identifier corresponding to the current location of the primary component of the art object title character varying(2048) NULL, title of the art object displayDate character varying(256) NULL, human readable date corresponding to the creation timeframe of the object beginYear integer NULL, computer readable year corresponding to the creation start year of the object endYear integer NULL, computer readable year corresponding to the creation finish year of the object visualBrowserTimeSpan character varying(32) NULL, a computer-generated timeframe slot assigned based on the begin and end year medium character varying(2048) NULL, materials comprising the art object dimensions character varying(2048) NULL, human readable dimensions of the art object inscription character varying NULL, text description of writings by the artist appearing on the art object and where they appear markings character varying NULL, text description of other visual marks appearing on the art object and where they appear attributionInverted character varying(1024) NULL, text describing the artist(s) primarily attributed with creating the work, inverted attribution character varying(1024) NULL, text describing the artist(s) primarily attributed with creating the work creditLine character varying(2048) NULL, acknowledgement of credit to constituents who provided or funded the acquisition of the art object classification character varying(64) NULL, type of art object subClassification character varying(64) NULL, sub-type of art object visualBrowserClassification character varying(32) NULL, slightly cleaned up / normalized and computed classification for the art object based on certain types of transformations and peculiarities with the original classifications assigned to art objects provenanceText character varying(max) NULL, the provenance of this art object described as a block of descriptive text – see also: objects_constituents where roletype is ‘owner’ for change of ownership records (when available) parentID integer NULL, parent object if one exists and foreign key to another row in this table isVirtual integer NOT NULL, 0 | 1 flag indicating whether this art object is a "virtual" object or not - see accompanying documentation for a description of what constituents a "virtual" object departmentAbbr character varying(32) NOT NULL, abbreviation for the NGA department with curatorial responsibility for this art object; for a list of NGA curatorial departments, please contact the NGA portfolio character varying(2048) NULL, portfolio associated with this art object for art objects associated with portfolios series character varying(850) NULL, series associated with this art object for art objects associated with series volume character varying(850) NULL, volume associated with this art object for art objects associated with volumes watermarks character varying(512) NULL, description of any watermarks that are present on the art object lastDetectedModification timestamp with time zone NULL, datetime stamp of the last detected modification of this object in the source system wikidataid character varying (64) NULL, Wikidata ID for NGA object. Not all objects are represented in Wikidata. customPrintURL character varying(2048) NULL if a custom print is available for an art object, this is the url for starting the process to order such a print ) CREATE TABLE objects_terms relationships between terms and objects The term column might contain embedded italics tags although this is rare ( termID integer NOT NULL, original term identifier in the collection management system; foreign key to terms_used table and terms_all table objectID integer NOT NULL, foreign key to the objects table termType character varying(64) NOT NULL, type of term, current consists of: Keyword Place Executed School Style Systematic Catalogue Volume Technique Theme none of these terms are currently mapped to open controlled vocabularies like Getty AAT or Getty TGN - we hope to get there in the not so distant future as well as to tag all of our objects more robustly term character varying(256) NULL, the actual term visualBrowserTheme character varying(32) NULL, a normalized theme that might be used on the public web site - should be re-modeled as a different term type visualBrowserStyle character varying(64) NULL, a normalized style used on the public web site - should be re-modeled as a different term type ) CREATE TABLE objects_text_entries stores long texts associated with objects ( objectID integer NOT NULL, foreign key to objects table text character varying NOT NULL, the text itself which may or may not contain one of several embedded formatting adornments textType character varying(32) NOT NULL, currently one of: bibliography brief_narrative conservation_note documentary_labels_inscriptions exhibition_history exhibition_history_footnote inscription_footnote lifetime_exhibition other_collections systematic_catalogue year character varying(4) NULL, the year the text was published ) CREATE TABLE preferred_locations public locations that are defined by content editors of the public web site - these are the preferred location descriptions and are geared for public consumption - they differ somewhat from the values in the collection management system ( locationKey character varying(32) NOT NULL, a unique key that is a shorthand abbreviation for the public location (should probably be the primary key since one is not defined) locationType character varying(32) NOT NULL, "room", "floor", or "building" description character varying(512) NOT NULL, preferred public facing description for the public location isPublicVenue integer NOT NULL, 0 | 1 flag indicating whether the public location is also used for public events, e.g. East Building Auditorium mapImageURL character varying(1024) NULL, full url to a map image on the public web site containing this location mapShapeType character varying(32) NULL, type of shape defined by map shape coords, currently one of: "poly", "rect", "circle" mapShapeCoords character varying(1024) NULL, CSV fragment defining a sequence of x,y coordinates defining the outline of the location on the map image partof character varying(32) This preferred location is part of another location referenced by this locationKey which is a key back into the same preferred_locations table – this enables the hierarchy of locations to be expressed in the data ) CREATE TABLE preferred_locations_tms_locations mapping between collection management system location IDs and preferred location keys ( preferredLocationKey character varying(32) NOT NULL, lookup key to preferred_locations table tmsLocationID integer NOT NULL, foreign key to locations table which is based on CMS location IDs PRIMARY KEY(preferredLocationKey, tmsLocationID) composite primary key ) CREATE TABLE published_images Images that have been published to NGA web properties either because the NGA owns the copyright or the images are being displayed in a much smaller resolution than the original images under fair use doctrine ( uuid character varying(64) NOT NULL PRIMARY KEY, A unique and persistent GUID for the image generated by the NGA’s web image publication system and stored in the digital asset management system iiifURL character varying(512). The base IIIF URL for the image (see https://iiif.io/api/image/2.1/ to access the image using the IIIF Image API) iiifThumbURL character varying(512). An example of the IIIF URL for the image that generates a small thumbnail sized to fit in a 200x200 pixel box viewtype character varying(32), One of “primary” or “alternate” – primary represents a primary view of an art object. Alternate represents an alternate view, typically from another angle, e.g., images from all angles around a sculpture sequence character varying(32), The order by which to sort images for a given subject, e.g., sequence of images around a sculpture would result in a rotational view around the sculpture. width integer, The full width of the IIIF source image if it is viewed at the highest zoom level and reassembled into a single image height integer, The full width of the IIIF source image if it is viewed at the highest zoom level and reassembled into a single image maxpixels integer, A limitation used to enforce fair use doctrine. When the width and height are larger than the max pixels setting, the image server will only permit sourcing of IIIF services from an image resized to fit within a box of this dimension. A customer might request a larger image to be produced via IIIF, but the resulting image will blur as the size increases since the source image size is restricted. created timestamp with time zone, Indicates the creation date of the actual source image uploaded to the NGA’s digital asset management system modified timestamp with time zone, Indicates the modification date of the image metadata record in the digital asset management system – dates tend to be more recent due to automated updates to metadata depictstmsobjectid integer, Records the Object ID in cases where the image depicts an art object stored in the CMS assistivetext text, Records text that would be useful to the visually impaired when used in combination with an assistive device list a screen reader );