Re: Review of 'Use Cases and Requirements for Ontology and API for Media Object 1.0', Working Draft 19 January 2009

Hello Michael,

thank you very much for your review.

Michael Hausenblas さんは書きました:
> All,
>
> As of my action [1] I was appointed to review your Working Draft from 19
> January 2009 regarding 'Use Cases and Requirements for Ontology and API for
> Media Object 1.0'.
>
> Short version: Nice use cases and good requirements. In order to increase
> readability, the content needs to be improved, esp. sections 1 to 4.
>
> Full version:
>
> ===============
>  Major issues
> ===============
>
> + Add a clear scope paragraph. I learned very late (somewhere in the section
> '1. Introduction') that you are actually mainly targeting videos.
>   

Agree.

> + Even though I always believed I know my work I was not able to decode:
> 'The "Ontology for Media Object 1.0" will address the intercompatiblity
> problem by providing a common set of properties to define the basic metadata
> needed for media objects and the semantic links between their values in
> different existing vocabularies.'
>
>  - what is 'intercompatiblity'?
>  - what are media objects?
>  - what are semantic links?
>   

Agree that this can be made clearer.


> + And it continues: 'The scope is mainly video media objects, but we take
> also other media objects into account if their metadata information is
> related to video.'
>
>  - how related?
>  - which metadata?
>   


For "how related" I would say "if the metadata information can also be 
applied to video, but not only to video, e.g. the creation date". For 
"which medata", this is a question to be answered in the future.

> + The figure in section '3 Purpose of the Ontology and the API' is nice but
> somehow questionable. Do user adapt the API? Do user visualise the API?
> Isn't the ontology itself the API? In which language (formal or logic-based)
> is it defined? What *is* the API?
>   

I think that the paragraph
"An important aspect of the above figure is that everything visualized 
above the API is left to applications, like: languages for simple or 
complex queries, analysis of user preferences (like "preferring movies 
with actor X and suitable for children"), or other mechanisms for 
accessing metadata. The ontology and the API provide merely a basic, 
simple means of interoperability for such applications."
Tries to answer some of your questions.
- Adaptation of the API: if the API is changed it is not the API we will 
have defined anymore.
- Visualize: see "... is left to the application", so "no"
- ontology = API: no, see also
http://dev.w3.org/2008/video/mediaann/mediaont-req/mediaont-req.html#req-r05
- "in which language ...": see as a potential example, which is neither 
formal nor logic-based
http://www.w3.org/TR/2008/REC-ElementTraversal-20081222/#interface-elementTraversal
- "what is the API". Again see
http://www.w3.org/TR/2008/REC-ElementTraversal-20081222/
As an example of an API specification we are aiming at IMO.

> + Rather than having an almost empty section '4 Terminology' that merely
> refers to RFC2119 you should use this space to define *your* terms (such as
> media object).
>   

Such a section will be part of the API and the ontology specifications.

> + In section '5.6 User generated Metadata' you use RDF/Turtle without any
> warning, hint or reference.
>   

Good point, a warning and references seem to be appropriate.

> + Regarding '6.7 Requirement r07: Introducing several abstraction levels in
> the ontology' I'd say this is an absolute must. 

Do you have any existing implemention we could look at to be able to 
judge the efforts of this?

> If you can't talk about the
> different abstraction layers, I guess the effort is pretty worthless.
>   

At the TPAC meeting in October we had a presentation from a video search 
engine with not more than *five*, "flat" properties, see
http://www.w3.org/2008/10/24-mediaann-minutes.html#item01
I think we saw a metadata mapping which was very useful and worth it, so 
I would disagree with your statement above.

> =================
>  Minor issues
> =================
>
> + the TOC is not well-formatted, although pubrule-checker [2] seems not to
> complain - rather use use <ol> and <li>
>   

mm ... I checked
http://validator.w3.org/check?uri=http://www.w3.org/TR/2009/WD-media-annot-reqs-20090119/
and did not see any problems. Could you point me to the markup part 
which you think has a problem?

> + in the section 'B References' the labels of [XGR Image Annotation] and
> [XGR Vocabularies] are mixed up (I think I remember seeing the latter
> document already, somewhere ;)
>   

Good point, to be fixed.

> + you want to go for a W3C Note, right? Then you want to remove the
> '(non-normative)' part in the references. You are not normative, hence as
> well not non-normative.
>   

I had thought so too, but see
http://lists.w3.org/Archives/Public/public-media-annotation/2008Dec/0084.html

> All this said I guess you need a major revision of this WD.

I did not see any comments on the requirements which I think are the 
most important "message" of the WD. Do you think these need a revision 
or are stable? How would you fill the beginning of sec. 6
http://www.w3.org/TR/2009/WD-media-annot-reqs-20090119/#requirements
"This sections describes requirements for the ontology and the API. The 
Working Group has agreed to implement the following requirements. "
...
"The requirements which the Working Group currently does not have 
agreement to take into account are the following:"

Felix

>  I think the UC
> and the requirements as they are present are valuable and convincing, but
> the reader needs more explanation in the beginning. You can't assume that
> everyone has followed your WG-internal discussions and instantly knows what
> you mean by media object or API.
>
>
> Tracker, this is ACTION-36 and I'm gonna close it.
>
> Cheers,
>       Michael
>
> [1] http://www.w3.org/2009/01/28-mediafrag-minutes.html#action01
> [2] http://www.w3.org/TR/media-annot-reqs/,pubrules
>
>

Received on Sunday, 1 February 2009 23:25:49 UTC