Metadata – use data discovery e.g. a library catalog data assessment determine the fitness-for-purpose of a data set data retrieval e.g., format
metadata … to accompany the data Original source Data processing lineage Data quality
More about metadata What – the title & description of the dataset. Why – reasons for the data collection. When - the dataset was created & updated.
More about metadata (2) Who – the originator and data supplier. Where - the geographical extent based on lat/long, co-ordinates, geographical names or administrative areas. How - to obtain more information or order the datasets inc. formats, media access, constraints.
Metadata standards & tools Dublin Core established some principles National standards e.g. US FGDC, UK NGDF & UK eGMS ISO ISO XML implementation schema e.g. UK Geo-Spatial Metadata Interoperability Initiative (UK Gemini) MetaGenie
Cost : Benefit Analysis Expensive to generate metadata represent a high level of abstraction and may need an expert to define But the benefits are substantial metadata make it possible to find data sets, and use them effectively they allow the benefits of investments in data to be realized
Gateways Metadata describe each data set But, how does a user know which metadata catalogue to search? ‘collection-level’ metadata describe the contents of entire collections… …meta-metadata e.g. UK Gigateway, Geography Network
The bigger picture: spatial data infrastructures National & regional NSDI (US) INSPIRE (EU) Global GSDI …a new Global Information Society?
Conclusions Metadata is important to Document data (good practice) Address heterogeneity Data & software components Address distribution Data & software Components It helps to develop Flexible solutions Evolvable solutions (future-proofing your investment in data acquisition)