80 likes | 170 Views
Access and Query Task Force Status at F2F1. Simon Miles. Starting point. The WG agreed to use the report of the W3C incubator group on provenance as a starting point for discussing access and query of provenance This refers to:
E N D
Access and Query Task ForceStatus at F2F1 Simon Miles
Starting point • The WG agreed to use the report of the W3C incubator group on provenance as a starting point for discussing access and query of provenance • This refers to: • Passing provenance of resource state representations via HTTP by value, by reference, or mixed • Embedding provenance or references to it in HTTP messages, or in HTML, RDF or other representations supporting embedded metadata • Negotiation over the kind, granularity and form of provenance they receive
Scope for F2F1 • For the first F2F, we solicited proposals to address two provenance access questions • Because they were inspired by the XG report, they made particular assumptions about the form of access information • The proposals did not all share the same initial assumptions, and so the questions were generalised to reflect this
Scoping questions • Given information regarding where to access data on the provenance of a resource state representation, what form does that information take and how do we obtain the provenance data? • How can a browser find the information on where to access provenance data, referred to above, for an HTML document that was downloaded, so that its provenance may be retrieved? • These questions were originally expressed with the assumption that the information took the form of an identifier for the representation, I, plus a location from which to retrieve it, L. The second question then assumed that I and L are embedded in the HTML document.
Summary of proposals • Use HTTP Link to give a URI for a thing’s provenance • Use HTTP to retrieve the provenance of a thing, given a URI for that provenance • Use HTTP to retrieve the location of a provenance service with data on a thing’s provenance • A provenance service as a SPARQL Graph Store or variant • A RESTfulprovenance service where the thing’s metadata expresses how to parameterise access • Use HTML Link to give a URI for a thing’s provenance • Use an HTML Profile for provenance metadata • User POWDER metadata to give a default provenance service • Use HTML Meta or microdata to give provenance access info
Suggested decision points (1) • There may be data regarding the provenance of a thing accessible from multiple sources. • The information required to obtain access to some provenance of a thing may be supplied in many different ways, and we do not aim to enumerate them all. • The WG effort will concern how the provider of a thing can supply information required to obtain access to some provenance of that thing (which may, as a side effect, include recommendations on how others can do the same).
Suggested decision points (2) • Regarding some provenance data obtained from dereferencing a provenance URI, calling a provenance service, or some other means. Which of the following is true? • (a) It is apparent from the data itself what single thing it describes the provenance of. • (b) Provenance data documents a set of things and how they are related by past occurrences, so to extract the provenance of any one thing requires knowing how it is identified in the data. • (c) Something else. • Regarding some provenance data obtained from dereferencing a provenance URI, calling a provenance service, or some other means. Which of the following is true? • (a) To meet the standard, it should be immutable. • (b) It can change over time without restriction. • (c) To meet the standard, there are particular ways in which it should not change, e.g. any one account should remain as it was
Future work and further issues • The TF needs to determine how it decides between competing proposals • This may mean • agreeing general points as above • adopting simple solutions before considering complex ones • justifying by reference to use cases • Other issues raised by the group: • Guidance for publishers of provenance • Provenance moving from one location to another • Specifying multiple provenance sources in one embedding • Ensuring data and provenance can be kept within the same file