An introduction to the MEDIN Discovery Metadata Standard

An introduction to the MEDIN
Discovery Metadata Standard
What is metadata and what should I do with it?
Put simply, discovery metadata is information about
a data set. For example, a metadata record
typically contains information about the title of a
data set, the geographic scope, when it was last
updated and the contact details of the person
who owns it.
Put another way, discovery metadata provides
information about, or documentation of, datasets
managed within an organisation or application.
Discovery Metadata Standard
Used to describe datasets (or series or services) so
that a user can easily discover them using a
portal and find details to where he/she can
access them
Standard composed of ‘elements’ (e.g. title, begin
date, contact, access conditions)
XML is used to encode the record so that it
becomes machine readable.
MEDIN has produced a guidance document,
validation tool (schematron) and tools to create
and test metadata records
Discovery Metadata Standard - Introduction
Discovery Metadata Standard - Guidance
Compliant with the
information –
Metadata), INSPIRE
and uses the ISO
19139 schema set
for encoding xml
Short, simple
version available!
Discovery Metadata Standard - Marine
The MEDIN standard specifies use of certain vocabularies (term
lists) to make it ‘marine flavoured’
Keywords: SeaDataNet parameter discovery vocab (e.g.
Fish taxonomy related counts; temperature of the water column)
Keywords: SeaDataNet vertical coverage terms (e.g.
epipelagic; benthic boundary layer)
Spatial Reference System: European Petroleum Survey
Group (EPSG) geodetic parameters (e.g. EPSG::4326)
Data format: MEDIN (e.g. delimited; image; GIS)
Organisations: SeaDataNet European Directory of Marine
Organisations (EDMO)
Discovery Metadata Standard - Tools
1. On-line metadata
2. Desktop tool –
Metadata Meastro.
Can work in stand
alone mode. Soon to
be extended to
Discovery Metadata Standard - Tools
A tool which will assist in transforming already populated
metadata databases into MEDIN format XML metadata.
Designed so that organisations who hold their own metadata can
transfer their data into this structure from which a tool can be
applied to produce xml records. Guidance document available.
Specific tools for GIS users: Stylesheet for transforming ArcCat
ESRI ISO standard metadata to MEDIN standard. Arc 9
stylesheet no longer supported. Arc 10 stylesheet now available.
Discovery Metadata Standard - Validation
Important to be able to test the structure and content of the xml
records once produced to ensure that they comply with the standard.
A Schematron has been developed (compliant with ISO 19757 (Part 3)
Information technology -- Document Schema Definition Languages
(DSDL) -- Part 3: Rule-based validation – Schematron).
Used in many different circumstances and tools so that if the standard
changes it only requires one update rather than various validation
methods for different applications
This schematron ‘sits’ at the end of the on-line metadata editor tool in
a validation step. Can be used by organisations to test transfer
between metadata holdings.
Discovery Metadata Standard - Schematron
Guidance document on the schematron – technical
Guidance document on using the schematron in software
‘Oxygen’ - aimed at more lay user.
What is a dataset?
• All metadata records can be harvested (and
produced primarily for) by the portal.
• It is important that the portal is not swamped with
records or not rich enough to be useful to the user
• MEDIN guidance on website
What is a dataset?
• the correct level for a dataset is a cruise,
survey or a set of repeat observations with a
common purpose,
• a data set usually constitutes a specificallyfunded piece of work,
• the dataset should be easily extractable
from a database for a 3rd party,
• if you are searching for a data set using a
portal and get the result every time you
search by different combinations of time,
location and parameter then it is probably
too coarse.
Updating the MEDIN discovery standard
• Standards evolve!
• MEDIN has placed itself to be close to, and feed into,
any changes in standard that could influence our
• Members of the MEDIN standards WG also are
represented on various Location Programme,
INSPIRE and BSI groups.
• Sign up to the e-mail list to be kept up to date of