Modelling the contents and structure of official statistics

Or: How to design ”correct” and globally consistent SDMX Data Structure Definitions

Or: Navigating in a space of statistical surveys of society

Or: Reality as a statistical construction

Bo Sundgren, Statistics SwedenICES-III, Montreal, June 18-21, 2007

Contents By Example (based on a simple generic model)

PERSONVARIABLE

VARIABLE

VARIABLE

VARIABLE

VARIABLE

x

m

>0

x

ORGANISATIONVARIABLE

VARIABLE

VARIABLE

VARIABLE

VARIABLE

x

p

<5

x

RESOURCEVARIABLE

VARIABLE

VARIABLE

VARIABLE

VARIABLE

g

PRODUCTVARIABLE

VARIABLE

VARIABLE

VARIABLE

VARIABLE

x

ACTIVITYVARIABLE

VARIABLE

VARIABLE

EVENTVARIABLE

VARIABLE

VARIABLE

RELATIONVARIABLE

VARIABLE

VARIABLE

x x

xx

Actors Utilities

Complexobjects

ProgramExecution.countunique(Provider.Id,

Program.Type,Program.Level,

Program.Orientation)

EducationProvider(Institution)

x Sector (Public/Private)

Teacher

x Sex

Provides

TeacherEngagement.count

x TeacherEdStatusx PartTimeStatus- PartTimeFraction.sum

EducationSystem(Utility)

- Country- Currency- CompulsoryEdBegAge- CompulsoryEdEndAge- CompulsoryEdLength- AcadYearBegMonth- AcadYearEndMonth

IsEngagedIn

EducationProgram(Utility)

- Name - Year - EntranceAge - Duration x Type x Level (ISCED97) x Grade x Orientation x PositionInDegreeStructure x FieldOfEducation

BelongsTo

Of

Pupil

x Sexx Agex CountryOfOriginx AttendedPrePrimary

PupilEnrolment.count

x PartTimeStatusx Repeaterx Completer/DropOutx CumulatedTime- PartTimeFraction.sum

IsEnrolledIn

Expenditure

x EducationalStatusx Sourcex Nature- Amount.sum

Funder(Actor)

x Sector (Public/Private/...)

Pays For

For

For

LEGEND:

one-to-many relationship

many-to-one relationship

one-to-one relationship

many-to-many relationship

x Variable: indicates that the ”Variable” variable has a classifying role

Object.count – indicates that ”Object” objects are counted

Variable.sum – indicates that the ”Variable” variable is summarised

reading direction

For

UNESCOmodelversion 1(to be revised)

Everything ”clickable”OBJECT

VARIABLE

Lefthand click Righthand click

Select:- object- variable

Retrieve metadata:- definition- value set, classification- questionnaire- quality declaration- survey documentation

Propositions

• The statistical data/metadata model presented here is general and domain-independent. It will cover all kinds of data and metadata to be made publicly available on the Internet and to be exchanged between national statistical agencies and international organisations. This proposition has been verified in a number of cases. So far the proposition has not been falsified in any case.

• This generic model can be transformed in a systematic way into an SDMX-compliant generic model expressed in XML.

• Since cube models, as actually practiced in national statistical agencies and international organisations, differ slightly between themselves and cannot always be said to be standardised, we propose the transformation to take place in two steps:

– Step1: Non-standardised cubes are transformed into normalised cubes as defined here.

– Step 2: Normalised cubes are transformed into standardised SDMX cubes (to be defined).