Content Model and Disability Evaluation Constructs (DEC) Inventory
DDI 3.0 Conceptual Model Chris Nelson. Why Have a Model Non syntactic representation of the business...
-
date post
20-Dec-2015 -
Category
Documents
-
view
215 -
download
3
Transcript of DDI 3.0 Conceptual Model Chris Nelson. Why Have a Model Non syntactic representation of the business...
DDI 3.0
Conceptual Model Chris Nelson
Why Have a Model
• Non syntactic representation of the business domain
• Useful for identifying common constructs– Identification, versioning etc.– “patterns”
• A good basis for designing syntactic representation (e.g. XML) schemas, databases, and processing systems– Industry tools support this process (e.g. EMF)
Variable
Scheme
Physical
Data Product
Physical
Instance
Archive
Study
Unit
Category
SchemeQuestions
DDI 2.0
•Driven by the need to archive data
•Developed as an XML DTD
•No formal conceptual model
•No re-use of artifacts
DDI 3.0 design goals – life-cycle model
The statistical production process (Secondary) use of dataArchiving
2.0
3.0
Variable
Scheme
Physical
Data Product
Physical
Instance
Archive
Study
Unit
Category
SchemeQuestions
DDI 2.0
Identification, Item Schemes, Item Scheme Associations
Component Schemes, Organisations
Group
Variable
Scheme
NCube Record
Layout
Physical
Data Product
Physical
Instance
ArchiveStudy
Unit
Data/Metadata Resource
Metadata
Report
DDI Base
Structural Metadata
Data/Metadata Management
Category
Scheme
Concept
Scheme
Data & Metadata
Structure
Question
BankInstrument
DDI 3.0
Identification, Item Schemes, Item Scheme Associations
Component Schemes, Organisations
Group
Variable
Scheme
NCube Record
Layout
Physical
Data Product
Physical
Instance
ArchiveStudy
Unit
Data/Metadata Resource
Metadata
Report
DDI Base
Structural Metadata
Data/Metadata Management
Category
Scheme
Concept
Scheme
Data & Metadata
Structure
Question
BankInstrument
DDI 3.0
In Line NCube Record
Layout
NCube TableLayout
NCubeLayout
Instrumentation module
A module in DDI 3.0 to describe survey instruments in a system independent way.
and others
To be used to drive data capturing systems or to pick up the output from these systems.
•Important metadata is entered at this stage and should be carried forward to the end data product.•Information about question flow, cues presented to the respondents etc. is important for the interpretation of the data•Often complex relationships between questions and variables.
Q
V
V
V
UML Constructs as used in the DDI Conceptual Model
Classes and Associations (1)
Variable(from VariableStandard)
ConceptItem(from ConceptStandard)
ConceptItem(from ConceptStandard)
Variable(from VariableStandard)
0..* 0..*0..*
+conceptualSemantic
0..*
0..*
0..1
1..*
1
zero or more
zero or one
one or more
one
cardinalities
Classes and Associations (2)- Aggregates
CategoryScheme
CategoryItem
1..*
0..1
CategoryItem is subordinate to and “belongs to” CategoryScheme
Aggregate by reference
Aggregate by value
In the model diagrams in this presentation there is no distinction made between aggregate by reference and aggregate by value. All aggregates are shown with a open diamond.
Classes and Associations (3)- Unidirectional
NCubeLogicalProduct VariableDataAttribute
0..*0..* 1
+takesSemanticFrom
1
Variable is navigable from DataAttribute but not vice-versa
Sub Classes - Inheritance
DimensionVariable
MetadataReport(from Metadata)
Variable+documentation
0..*0..*
DimensionVariable inherits from Variable (i.e. it is a “specialisation” of Variable). Therefore DimensionVariable can have an association to MetadataReport. However, any associations from DimensionVariable are specific to DimensionaVariable and are not applicable to Variable
Abstract ClassesIdentifiableArtefact
id : Stringuri : Stringurn : String
Instrument(from DataCol lection)
Instrument(from DataCollection)
InternationalString(from DDI_Base)
IdentifiableArtefact
id : Stringuri : Stringurn : String
0..1 0..10..1
+description
0..1+name
0..1 0..10..1 0..1
An abstract class is drawn because it is a useful way of grouping classes, and avoids drawing a complex diagram with lots of association lines, but where it is not foreseen that the class serves any other purpose (i.e. it is always implemented as one of its sub classes).
Here Instrument inherits the attributes of Id, uri, urn.
Instrument can have a multilingual name and description.
SoftwarePackage
contains metadata attribute values for:
MethodologyCollectionEventNoteUniverseOtherMaterial
QuestionItem
QuestionConstruct ComputationItem Loop
MetadataReport(from Metadata)
DataCollection
Instrument
IfThenElse
ControlConstruct
Sequence
type : String
DisplayText
StatementItem
description : StructuredString
11
+documentation
0..*
0..*
0..*
0..*
0..*0..*
0..*0..*
+thenCondition
11
+elseCondition0..10..1
0..*0..*
11
Instrument - Simplified Class Diagram
Question Bank - Simplified Class Diagram not in the schemas
here the multiple question item can (must) have at least one sub item which can be another multiple or a single question. At the bottom of the tree there will be only single questions
Metadata forQuestion IntentVisual AidResponse UnitAnalysis Unit
ResponseDomain
MultipleQuestionItem
sequence : Integer
QuestionText
QuestionBank
MetadataReport(from Metadata)
QuestionItem
0..*0..*
1..*
+sub question
1..*
0..*0..*
0..*
1
0..*
1
0..*
+documentation
0..*
Variable(from VariableStandard)
ConceptItem(from ConceptStandard)
0..*0..*
0..* 0..*0..*
+conceptualSemantic
0..*
Variable - Simplified Class Diagram metadata forDefinitionUniverseEmbargoResponseUnitAnalysisUnit
Metadata forDescription(Formal) Derivation Rules
VariableScheme
MetadataReport(from Metadata)
MetadataReport(from Metadata)
ConceptItem
QuestionItem
VariableConcatenation
DerivedVariable
+documentation0..10..1
Variable
0..*
+documentation
0..*
0..*
0..*
+conceptualSemantic
0..*
0..*0..*
+usedBy
0..*
0..10..1
0..1
+valueStoredIn
0..1
1
1..*
1
1..*
Representation
VariableRepresentation
0..10..1
0..10..1
0..10..1
Identifying potentially comparative data• The grouping mechanism can be used to mark up families of studies that
from the outset have been designed to be comparable.
• ...or families of studies that has been made comparable through a harmonization process.
• However, none of these mechanisms reach beyond the limit of the DDI 3.0-wrapper that binds the family of studies together.
• One of the biggest challenges for DDI 3.0 has been to define a way to describe relationships between variables across DDI-wrappers,
collections and servers.
• Use-case: “Give me more variables like this”, in other words the ability to identify potentially comparative variables across studies, collections, archives and locations.
Identifying potentially comparative data
• There is a mechanism in the existing DDI that to a certain degree will allow you do this. That is the ability to assign concepts from external vocabularies to variables.
Study 1
V1 V2 V3
Study 2
V4 V5 V6
External vocabulary
C1
C11 C12 C13
ConceptItem
Variable
+conceptualSemantic
0..*
0..*
0..*
0..*
• In DDI 3.0 there will a more elaborated solution to the same problem, a specification of an external registry-like question-bank or classification database that will allow you to register concepts, questions and variables.
• The specification can be used to set up local question banks or question banks that are global to many organizations.
• The specification will also support statements about differences between registered variables
Study 1
V1 V2 V3
Study 2
V4 V5 V6
Identifying potentially comparative data External registry
I1 I2 I3 I4
Diff• The registry can be seen as an extension to a standard DDI document.
• ...but the specification might also include the interfaces to allow this to be set up and run as a proper registry on the Web.
Registries• Contains metadata that allows users/ applications to find things• The objects themselves do not need to be in the registry
– But must be accessible over the internet (preferably accessible by standardised queries and retrievable in a standardised format)
– E.g. questions in question bank category schemes variables
• Registries can have repositories to store local content• Registry standards exist and registry products are available
– But they need to be customised to support the domain(e.g. customised software that understands the DDI model and syntax implementation)
• If objects can be identified in a globally unique way, then they can be accessed and shared
Data Analysis
Data & Metadata
Structure
Physical
Data Product
NCube Record
Layout
Cube Structure - Simplified
metadata for
UniverseDefinition
can also link to a Variable
metadata for
UniverseDefinitionImputationResponseUnitAnalysisUnitPurpose
Constraint
DimensionVariable(from VariableStandard)
AttachableArtefact
CoordinateGroup
NCubeLogicalProduct
Dimension
NCubeStructure
MetadataReport(from Metadata)
Label
Measure
DataAttribute
MetadataReport(from Metadata)
Variable(from VariableStandard)
0..*
0..*
+takesSemanticFrom
1
+attachesTo
1
0..*
0..10..*
0..*
0..* 0..*
1
1..*0..1 1..*0..1
{ordered}
0..*
0..*0..*
0..*
0..1
0..*
0..1 {ordered}
1
0..1
+documentation0..*0..*
0..10..1
0..1
0..*0..*
0..10..*0..*
1
1
0..*0..*
+documentation
0..*0..*
+takes SemanticFrom11
+takesSemanticFrom
11
AttachableArtefact
Measure Dimension CoordinateGroup
DataAttributeDimensionMeasure
MeasureItem AttributeItem
ItemValue
ReferencedValue
Data Structure
CubeCoordinate
EmbeddedDataValue
Variable
CoordinateVariable
1+cubeCoordinateVariable
1
NCube Record
Layout
NCube Logical
Product
Physical
Instance
Cube Data – Contains or Points to Data
EmbeddedDataValue
value : String
ValueLocation
startPosition : Integerwidth : IntegerdecimalPosition : IntegerdecimalSeparator : StringgroupingSeparator : Stringdelimiter : StringvariableNamesSpecified : BooleanexplicitDataType : String
ColumnPosition
columnPosition : Integer
ReferencedValue
Variable(from VariableStandard)
CoordinateVariable
1
+cubeCoordinateVariable
1
Dimension(from LogicalProduct)
DataAttribute(from LogicalProduct)
CubeCoordinate
number : Integer
1
+valueFor
1
AttributeItem
1
+valueFor
1
Measure(from LogicalProduct)
ItemValue
{TabularNCube}
11
11
MeasureItem0..*
+attribute
0..*
1
+valueFor
1
11
itemValue
Link to the Cube Structure Definition
DDI 3.0 Metadata• Metadata constructs that are fairly generic and can be attached at various places in the
hierarchy.• Examples:
– Coding instructions– Description of time and geography– Citation/Abstract– Methodology etc.
• The DDI model contains a metamodel for metadata structures:– Identifies the object types to which metadata can be attached– Specifies the category/concept schemes that contains the list of valid identifiers for the object
types– Specifies the metadata reports that can be made (e. g. coding instructions, citation) in terms of
• Attributes• Value domain (e.g. format) of the attributes• Reporting hierarchy of the attribute
– Identifies to which object types the metadata report can be associated
Metadata Attributes
Object Identifier
Metadata Structure Definition
Identifier ComponentsItem Scheme
uses defined concepts
defines the object types to which metadata can be “attached”
specifies to which object types the
report can be “attached”
identifies the value domain of the
component
Metadata Report
Concept Scheme
concept defined inConcept
takes semantic and context
from
Target Object Type
identifies target object type of the
component
can have hierarchy
Format and Permitted Value List
Value domain
identifies target object type of the
identifierSpecifies
components for each Object (“key”
Metadata Structure
+takesSemanticFrom
this can be any object in the DDI model, including a specific DocumentableArtefact, thus allowing a report to be attached to or referenced from, another report
ObjectTypeScheme(from DDI_Base)
ItemScheme(from DDI_Base)
IdentifierGroup
IdentifiableObjectType(from DDI_Base)
1..*
1
1..*
1
IdentifierComponent
1..*
1
1..*
1
1
+targetClass
1
0..1
+valueDomain
0..1
AttachmentStatus
isMandatory : Boolean
MetadataStructureDefinition
1
1
1
1
IdentifiableObject
1+targetClass
1
1..*
1
1..*
1
1..*
1..*
1..*
1..*
DocumentableArtefact
Type(from DDI_Base)
Representation(from DDI_Base)
ReportStructure
1..*1..* 1..*
+attachesTo
1..*
1 1
+structureFor
1 1
ConceptItem(from ConceptStandard)
MetadataAttribute
isMandatory : Boolean
0..1
+localType
0..1
0..*
1
+child
0..*sub-structure
+parent1
0..1
+localRepresentation
0..1
1..*1..*
11
e.g. CitationCoding InstructionsUniverseAbstract
+specifies +uses
Metadata Set – Contains Metadata Reports
0..* 1
MetadataAttribute1
1ReportStructure
1..*
MetadataSet
MetadataAttributeValue
MetadataReport
1
1..*
1
1..*
1..*1..*
AttachmentKey1..*
+objectIdentifier
1..*
IdentifierComponentValue
1..*1..*
MaintainableArtefact(from DDI_Base)
IdentifiableArtefact(from DDI_Base)
1IdentifierComponent
0..*
1..*
IdentifiableObject
1
shows the link to the metadata structure definition
Modularity and grouping as a way to handle comparative data
Ques-
tions
Study
design
Variab-
les
Group
French
study
German
study
UK
study
Spanish
study
Italian
study
Extentions
Local
overrides
Extentions
Local
overrides
Translation
Extentions
Local
overrides
Translation
Extentions
Local
overrides
Translation
Extentions
Local
overrides
Translation
Modularity and grouping as a way to handle multiple tables/cubes
Variables
Study
description
nCube3nCube 2nCube1 nCube5nCube4
Table
description
Table
description
Table
description
Table
description
Table
description
Group
Category
Schemes
Group: Logical Combination of Artifacts
0..1
Metadata forCitationPurposeAbstractUniverseOtherMaterialNote
Metadata forItemDetailsAccessOtherMaterialNote
DataCollection(from DataCollection)
StudyUnit(from StudyUnit)
Archive GroupType
time : TimeTypeinstrument : InstrumentTypepanel : PanelTypegeography : GeographyTypedataset : DataSetType
ConceptualComponentSet(from ConceptStandard)
LogicalProduct
MetadataReport(from Metadata)
QuestionItem(from DataCollection)
Group
0..*0..*
0..*0..*
0..*
1
+child0..*
subGroup
+parent
1
1..*
1
1..*
1
11
0..*0..*
0..*0..*
0..*0..*
ConceptScheme(from ConceptStandard)
CategoryScheme(from CategoryScheme)
Variable(from VariableStanda...
Study(from StudyUnit)
ComparisonStandards
1..*1..*
0..1
1..*1..*
0..*0..* 1..*1..*0..*0..*
Thank You