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Statistical databases in theory and practice Part III: Designing statistical databases

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## Statistical databases in theory and practice Part III: Designing statistical databases

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**Statistical databases in theory and practicePart III:**Designing statistical databases Bo Sundgren 2008-02-11**Conceptual data model and relational data model in**normalised form.**Concept modelling**• Define concepts and relations between them • Conceptual models and data models • Visualise models graphically**one-to-one, symbolised by “arrow-to-arrow”**one-to-many, symbolised by “arrow-to-fork” many-to-one, symbolised by “fork-to-arrow” many-to-many, symbolised by “fork-to-fork” Relations between two object types Note: The relation is usually not a flow relation! (But you should tell what kind of relation it is.)**Concept modelling: Exercises**• B2B • The customers of companies are companies • Companies have employees (persons) • B2C • The customers of companies are consumers (persons) • Companies have employees (persons) • B2B+B2C • The customers of companies are companies or consumers (persons) • Companies have employees (persons) • Hint: There are two basic object types, COMPANY and PERSON in all three examples**Different roles of concept modelling**• Clarifying a small number of related concepts • Information model for an application • defining meaning • basis for data design • Corporate information model • for more efficient communication between people • basis for system integration**Modelling the contents and structure of official**statisticsOr: How to design ”correct” and globally consistent SDMX Data Structure DefinitionsOr: Navigating in a space of statistical surveys of societyOr: Reality as a statistical construction Bo Sundgren, Statistics Sweden ICES-III, Montreal, June 18-21, 2007**What can a statistical agency do, in order to help a user -**find potentially relevant statistical data? - judge the relevance of data retrieved? • Provide overviews of available data • Provide search tools • Provide informative metadata**Conceptual navigation: contents exploration and searching**for statistics • A conceptual model of societyas reflected by official statistics**Contents By Example (based on a simple generic model)**Complex objects Utilities Actors**Everything ”clickable”**OBJECT VARIABLE Righthand click Lefthand click • Select: • object • variable • Retrieve metadata: • definition • value set, classification • questionnaire • quality declaration • survey documentation**UNESCO**model version 1 (to be revised)