Re: [help-GIFT] Understanding MRML: query-paradigm

[Ralf Juengling]

Hi all,

On Mon, 2002-07-01 at 07:15, Wolfgang Müller wrote:
> > Think for instance of a the two classical query schemes "query by
> > keyword" vs "query by example". I can imagine an MRML-compliant client
> > which is supposed to merely support keyword queries. When it connects
> > to a CBIRS which on the other hand merely supports QBE, it should be
> > able to recognize that no queries can be made.
> > If this isn't determined by the "query-paradigm" elements, what is
> > the way to go?
> 
> It should be determined by query-paradigm elements.

to push the discussion a bit, I come up with a concrete proposal for
the "query-paradigm" elements:

The current spec is as follows:

<!ELEMENT query-paradigm-list         (query-paradigm*|error)>

<!ELEMENT query-paradigm  (error?)>
<!ATTLIST query-paradigm  query-paradigm-id CDATA #REQUIRED>
                      
However, in MRML-messages sent by gift, the "query-paradigm-id"
Attribute is denoted "type"; since it is also potentially
referenced in the get algorithms message,

<!ELEMENT get-algorithms EMPTY>
<!ATTLIST get-algorithms collection-id     CDATA #IMPLIED
                         query-paradigm-id CDATA #IMPLIED
>,

I propose to rename it again to "query-paradigm-type", thus:

<!ELEMENT query-paradigm-list         (query-paradigm*|error)>

<!ELEMENT query-paradigm  (error?)>
<!ATTLIST query-paradigm  query-paradigm-type CDATA #REQUIRED>,

<!ELEMENT get-algorithms EMPTY>
<!ATTLIST get-algorithms collection-id       CDATA #IMPLIED
                         query-paradigm-type CDATA #IMPLIED
>.


I propose to prescribe the legal values of the "query-paradigm-type"
attribute in the MRML specification as one of the follows:
"query-by-keyword"
"query-by-example"
"select-by-constrain"
"browse-collection"


Another issue are attributes of a query-paradigm elememt, as Wolfgang
already pointed out in a related thread.

[copied from another thread]
> > Could you give an example of an algorithms property which you would
> > like to put into the query-paradigm-list?
> 
> The way interaction works, the indexes the algorithm expects.
> 
> For collections: the data types we can get out of it.

With respect to some former discussion, one can find here,
http://mail.gnu.org/pipermail/help-gift/2002-March/000189.html
I see what you mean (thanks, Wolfgang).

At the moment however, I have no tighten opinion on this point (whether
it's good to put it into query-paradigm or not; have to think about it).

However, I also feel, more people should participate the discussion.

Cheers,
Ralf