Daniel Schwabe wrote:
Sherman,
as another alternative, I urge you to take a look at Explorator [1]
(there is a short movie explaining the basic idea, you can also play
with the live interface), which can do all of what you said, and more.
It provides a more general exploration paradigm, of which the example
you give below is only one of the possibilities...
Best
Daniel
[1] http://www.tecweb.inf.puc-rio.br/explorator.
Daniel,
When you speak to the <http://lod.openlinksw.com> instance, do you use
SPARQL Protocol or the Faceted Browsing REST API or either depending on
task ?
I suspect SPARQL protocol, but please confirm.
Kingsley
Sherman Monroe wrote:
Dan,
...
As for pivoting and set-based browsing in general, it's a very novel
paridigm that requires more study, espeically user-oriented studies.
It's easy to mis-apply old methods to this new UI approach, for
example, how Parallax creates a 1-dimensional (i.e. 2-directional)
breadcrumb trail. This is borrowed from WWW browsing, where the only
directions from the "subject" (i.e. web page loaded) is back and
forward. But in a linked database, the number of directions from a
subject is equal to the number of possible types of the links from
that subject to its objects. So it's a truly n-dimensional
hyperspace. Thus, the 2D-breadcrumbs trail, while helpful, does not
truly orient user's current position in the database. Here is my
attempt to describe how navigating the linked dataspace would feel in
real life, to better bring out the point. Image a linked database as
a building, and each room contains a set of one or more resources
matching a SPARQL criteria, and along the walls of the room are
portals leading to other rooms, where each portal represents an RDF
property those resources share. Now say I'm browsing a social network
database, and I'm in DanBrickley's room, and I open and enter his
*foaf:knows* portal. Now I am in /DanBrickley >> foaf:knows/ portal.
The portals in here represent all the properties shared by all the
folks Dan knows. Where can I go? I can go back through the
DanBrickley portal, or through one of the property portals. Now here
is the magic introduced by the structured XML SPARQL query. Suppose
that from here, I want to enter the *foaf:interest* portal. In there,
I see /semantic web/. Now I kick out all the other resources in this
room, so that only semantic web remains. If I go back into the
*foaf:interest* portal through which I came, I now find this list of
friends is narrowed to just those whose interest is semantic web. The
abilty to manipulate a room and have it affect the state of all other
rooms in my breadcrumbs, is something you can't currently do with
Parallax, because of it's 2D navigational path (David or anyone, I
make this statement after having tried witht he interface myself, the
browse all>> link on properties is the cloest thing I found). Now
from this room (the /friends whose interest is semantic web/ room), I
now go through the *foaf:currentProject* portal. I have now forked my
criteria (an ability that was in Piggybank/Longwell, but missing from
Parallax for some reason). Here I find the /Umbel Project/. Because
each resource also acts like a portal (thanks to resource dereference
:), I enter the /Umbel Portal/, and now I'm in a new room inside a
totally new building containing rooms specialized around technology
projects (a building represents a SPARQL endpoint, linked database
source, an RDF graph, etc). So the portals can lead into/out of any
building imaginable. Parallax only allows for navigating inside one
building, i.e. Freebase, a second short coming.
Not to pick on Parallax at all, it's outstanding work that must
continue to be pushed and improved, so I'm just here to whet the
concepts it introduces. I have found the above visualazation of the
linked database helpful in my work with linked data browsers, most
recently razorbase. I've toyed with the notion of a 3D linked data
browser along these principles, but don't know if that could actually
be more useful than simple tables for large audiences.
--
Regards,
Kingsley Idehen Weblog: http://www.openlinksw.com/blog/~kidehen
President & CEO
OpenLink Software Web: http://www.openlinksw.com
