in Core properties may be supplied on a record-by-record basis or as a set of default values within the metadata for the entire data set.
The ALA will be able to use OAI-PMH or the tab-delimited/comma-separated data set to harvest basic metadata about the multimedia objects in a collection.
This same set of Dublin Core properties can also be used for registering a single multimedia object as an online resource.
The ALA will use a range of standard approaches to link to data resources. Each has particular benefits.
In addition to those protocols addressed in the following subsections, the ALA expects to support the Open Geospatial Consortium (OGC) Web Feature Service (WFS) for exchange of species occurrence data (using properties from the Darwin Core or the TaxonOccurrence vocabulary). Specific recommendations will be added at a later date on the use of WFS and other OGC standards.
TAPIR is the current version of the remote query protocol developed and promoted by TDWG. It is effectively an enhanced replacement for the two earlier TDWG data access protocols, DiGIR and BioCASe. The ALA will interface with existing DiGIR or BioCASe resources but recommends the use of TAPIR for future implementations.
TAPIR is a general-purpose language for querying remote databases and for retrieving data in formats suited to the needs of the requestor. It relies on the existence of agreed community data models. Each such model provides a set of agreed properties which can be mapped against a range of distributed databases, even though their underlying data structures may be very different.
For example, a collection database, an ecological data set and a repository of biodiversity image metadata may all contain fields which represent the scientific name of an organism and the spatial coordinates and date associated with a particular occurrence of that organism. TAPIR allows all of these databases to advertise the fact that they have records containing fields which correspond to the ScientificName, EarliestDateCollected, Latitude and Longitude concepts from a model such as the Darwin Core. A client application can then send standard requests (as XML documents or a set of parameters encoded in a URL) to each of these resources and receive the results back as an XML response document. The format of the response document and the data elements to be inserted into this format can be defined by the client requesting the data. This makes it possible, for example, for the client to request the results as a KML file which can be displayed directly in Google Earth or Google Maps.
TAPIR supports five types of request:
Several implementations of the TAPIR protocol are available. The TAPIR server implementations all include configuration interfaces to assist data providers in mapping their relational databases to standards such as Darwin Core, ABCD and the TDWG TaxonOccurrence vocabulary. Available software includes:
The ALA is working with GBIF and others to simplify the installation and use of these tools.
For more information on TAPIR, see:
TAPIR is a powerful tool for supporting remote access to a database but some data providers may not need the flexibility it offers, or may be unable to run the TAPIR software on a web server. In such circumstances it may be simpler to share a flat file representation of the data. The simplest approach, supported by database and spreadsheet software, is to export the content as tab-delimited or comma-separated data and then to register a URL from which the data file can be downloaded. This makes it possible to associate the data with any relevant descriptive metadata. Note that data should always be shared using UTF-8 as the character encoding.
One possible weakness in such an approach is that it may be difficult for users to interpret the significance of the various columns in such a data set. The ALA makes the following recommendations to address this problem:
The property identifiers should be constructed using either the short or long form specified in this table. The long forms are formal URIs and are preferred