1.1 Metadata strategy
There were three principal reasons to implement metadata in the Croatian Central Bureau for Statistics (CBS):
- to standardize definitions across all statistical activities
- to move the production of statistics closer to the subject-matter experts in order to speed up the statistical survey life cycle
- to present statistics on internet along with its context in order to make statistics understandable and available to users of all types, i.e. to extend the use of statistics beyond the usual statistical publications
The strategy document was prepared in CBS already in 2001 1. In 2002, a framework agreement was signed between the Division for Western Balkans at the Swedish International Development Cooperation Agency (Sida) and Statistics Sweden's International Consulting Office (ICO). In this framework the Swedish Statistical Office (SCB) provided support for the creation of the public macro database and a central metadata repository in CBS. In its final phases (2006 - 2007) the project was extended to support the development of the Integrated Statistical Information System (ISIS).
1. Zdenko Milonja: Information System Development Strategy, CBS, July 2001.
1.2 Current situation
The central metadata repository (CROMETA) is the essential part, the core of the Integrated Statistical Information system (ISIS) which is in the final stage of development. In other words, ISIS is developed upon CROMETA.
The original idea - to develop an automated statistical survey processing system on the client/server platform - resulted from the operational circumstances in CBS:
- the IT sector is strictly centralized, i.e. IT sector processes all statistical surveys upon the descriptions laid out by statisticians.
- the majority of statistical surveys are still processed on the mainframe
- the majority of surveys have similar processing stages (data entry, validation, correction, tabulation, dissemination); therefore the majority of corresponding data processing jobs have similar structure which could be incorporated in a generalized solution. Such a solution was developed in CBS for data processing on the mainframe in the 80s and is still in use.
The metadata repository must contain all the necessary information to be used as parameters for a general 'program' that produces specific operating procedures for particular surveys. Therefore it could be stated that centrally stored metadata could more or less automatically 'drive' the statistical production system. This is the basic purpose that initiated the metadata system development in the first place. Naturally, the idea was extended to cover all aspects of statistics, as laid out in the Reference ModelTM resulting from the MetaNet project within Eurostat (2000-2003).
The CROMETA model contains Reference ModelTM concepts extended and customized for CBS needs as well as specifics of a previous CBS metadata model and specifics needed to run PC-Axis as the main dissemination tool. Although the model is very complex and rather demanding to comprehend, it proved to be well conceived from the beginning, or rather from the moment we fixed the 'big picture'. Now the metadatabase is stable, with high tolerance for occasional changes that occur along with development of specific solutions for particular stages of the statistical life cycle.
The central metadata repository is presently rather empty since it is still in test phase, it contains data on just a few statistical surveys that were selected as pilots. We are well aware of the problems which may arise among statisticians with the obligations to enter or transfer all the 'knowledge' of all statistical activities.