13-14 December 2012 SDMX Technical Working Group Paris WP Item 6 Expressions and Calculations

13-14 December 2012 SDMX Technical Working Group Paris Goals of the WP item (1) Adopt a Language for Calculations and Validations, as envisaged in the package n.13 of SDMX Information Model The SDMX package n. 13 – Transformations and Expressions – is a generic model aimed to track the derivation of data, derived from the CWM (Common Warehouse Metamodel), a OMG standard (Object Management Group) widely used in the IT field

Goals of the WP item (2) Make it possible to define and exchange the algorithms either used or specified for calculating data and the coherence rules, either enforced or looked-for between different data 1.Design the language for defining expressions (expression language) – that is the list of the operators available and their formal grammar 2.Design the IT formats (messages) for exchanging the definitions of the Transformations (calculations and validations defined by means of expressions)

13-14 December 2012 SDMX Technical Working Group Paris SDMX IM – Package 13

December 2012 SDMX Technical Working Group Paris 5 Transformations; internal view Einstein equation E = MC 2  E = M*(C**2) Operator: ** b p Operand: 2 Operand: C Result: E Operator: * f f Operand: M Constant node Reference nodes Operator nodes Expression nodes 0..*

December 2012 SDMX Technical Working Group Paris 6 Transformations: User view Einstein equation E = MC 2  E = M*(C**2) Operand: 2 Operand: C Result: E Expression: E = M*(C**2) Operand: M

December 2012 SDMX Technical Working Group Paris 7 Notes on Transformations The Operands may be: Artefacts of the model (e.g. Statistical Data) Constants Operator nodes The property of “Closure” The result is an artefact of the model (e.g. Statistical Data) The result may be operand of other calculations

December 2012 SDMX Technical Working Group Paris 8 Graph of the calculations External Institutions C1C1 C2C2 C3C3 C4C4 C5C5 T1T1 T3T3 T2T2 C10C10 C 12 C 13 C 15 C 17 C 16 T 13 T 12 T14T14 Banks & OFI’s reports C.C.R. C 21 C 22 C 23 C 24 T 22 T 21 C 51 C 52 T 53 T 52 T 51 Economic research models C 54 C 53 T 54 C 60 C 61 Statistical bulletin T 60 T 61 Statistical products C 70 T 71 T 70 T 72 C 71 C 72 C 41 T 42 T 41 C 42 Supervision models

13-14 December 2012 SDMX Technical Working Group Paris Validation as a Calculation Formal (Structural) –assurance that the formal structure of the data observations matches the Data Structure Definition, in term of concepts, their roles and their admissible values; the formal validation is not a calculation and is not defined through an expression; Of the Information Content (Plausibility) –Assurance that the data content gives right information about the real world (as much as possible); to this end, it is possible to use the a-priori information about the real world and the possible redundancies of the data (e.g. the integrity rules, coherence rules, plausibility rules); this kind of validation rules is normally performed through calculations,

December 2012 SDMX Technical Working Group Paris 10 Validations as calculations Use of the same language of the calculations Validations possible in any phase of the process Results of the Validations like any other data are defined and stored can be inquired and disseminated can be further processed

December 2012 SDMX Technical Working Group Paris Main goals fot the TWG meeting Share information on the existing languages (input from the Secretariat: not reinvent the wheel and start from existing experiences) : –Presentation of ESS VIPV project –Presentation of XBRL formula –Presentation of Banca d’Italia EXL Share the general principles and requisites of the solution Share the working programme for this item, involving the SWG

December 2012 SDMX Technical Working Group Paris WP Item 6 Expressions and Calculations