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FW: empty metadata elements

From: Scarlett Julian (ED) <Julian.Scarlett@sheffield.gov.uk>
Date: Mon, 10 Feb 2003 13:35:27 -0000
Message-ID: <F9BE3B1AB649D311A573009027852E4D0287951A@EDUC_MXS>
To: "'w3c-wai-ig@w3.org'" <w3c-wai-ig@w3.org>

Yes Chaas,  you're right it does belong on the list. 

Scenario: A hypothetical CMS author who has no understanding of accessibility standards doesn't put anything in the field for the DC.acessibility meta element when adding a new page and the CMS includes the following in the mark-up:

<meta name="DC.accessibility" content="" /> 

This categorically states that the pages conforms to no accessibility standards at all and a screenreader user thinks "I'm not going there because I might not be able to access the content and I'll go elsewhere in this long list of search results"  However, in reality the page is actually compliant to all priority 3 guidelines and would have been the best and easiest way for the user to access the information if only the CMS author had known the implications of not filling that certain field in...

Moral: train the CMS authors to fill in the metadata correctly. 

BUT In this case wouldn't not having the metadata on the page at all have been more useful to the end-user. We all know how people work in real-life and with the best training in the world there will always be instance where a certain field is not filled in either through laziness, pressure, ignorance etc etc.

OK, I'm playing Devil's Advocate here but this is an area where there seems to have been very little discussion and it's a very real problem for me at the moment.

Initially I thought the practice of making the statement that certain metadata was null was good but I can see at least one instance where it might not be. Are there any types of metadata where the lack of that positive statement would be more beneficial than detrimental. And vice versa?

Thoughts?

--J.

-----Original Message-----
From: Charles McCathieNevile [mailto:charles@sidar.org]
Sent: Monday, February 10, 2003 1:06 PM
To: Scarlett Julian (ED)
Subject: Re: empty metadata elements


I think it is worth keeping this on list myself - feel free to forward 
this back to it with further response...

If you claim that a page has a null author, or that there is no actual 
value for the copyright over the page, then people are likely to 
interpret that. Since you are using a system designed for machine 
interpretation you should expect machines to interpret it, rather than 
people somehow having a similar understanding of an edge case to your 
understanding.

If I buy a piece of software and it says "copyright restrictions: none" 
and act on it, many people would suggest I was being reasonable in 
copying it. If I find a page that claims that there are no 
accessibility barriers present or that it conforms to no accessibility 
requirements, I may well act on those. For example waste time trying to 
read the page, or needlessly avoid it because I need things which meet 
some requirement for have text equivalents to images.

On the other hand if there is no statement I just assume that you don't 
know.

In a CMS it is important not to put in false statements - so you need 
to distinguish the case of not having a complete statement from having 
a complete but null statement. Consider the alt text example again - 
ATAG requires that tools do not include default values, because it is 
then impossible to know if the default is there because it is accurate 
or just because no meaningful value has been offered.

Consider also that metadata can come from multiple sources - as an 
author it is is your interest to have a reputation for producing 
reliable metadata about your own content unless you prefer that people 
look for other people's information first.

cheers

Chaals

On Monday, Feb 10, 2003, at 23:34 Australia/Melbourne, Scarlett Julian 
(ED) wrote:

> Chaas
>
> thanks for replying. I've taken the discussion outside of the list 
> because it doesn't appear that this issue will have accessibility 
> repercussions (correct me if you think otherwise and I'll CC the list 
> in later). Nevertheless I'm still wanting to know whether making the 
> statement that the page has or is a foo with a null value is different 
> to not explicitly making that statement. How would that statement be 
> interpreted? It seems to me that there is really very little practical 
> difference but I'm just looking for someone to confirm that for me.  
> Perhaps some background will help: we are just about to implement a 
> Content Management System which allows authors to insert their own 
> values for certain meta elements. However if they choose not to enter 
> a value then the CMS puts in a null value rather than not including 
> the element at all in the mark-up. Before we go ahead and enter a 
> fully qualified Dublin Core schema plus some others I just want to 
> know what the repercussions might be.
>
> thanks
>
> Julian
>
>> -----Original Message-----
>> From: Charles McCathieNevile [mailto:charles@sidar.org]
>> Sent: Monday, February 10, 2003 11:57 AM
>> To: Scarlett Julian (ED)
>> Cc: 'w3c-wai-ig@w3.org'
>> Subject: Re: empty metadata elements
>>
>>
>> It  would imply to me that the page has or is a foo, with a
>> null value.
>> Sort of like <img src="bar" alt="" /> implies that the image
>> at foo has
>> a text equivalent of nothing (i.e. it doesn't mean anything).
>>
>> This means you are making a statement, and should expect it to be
>> interpreted as as such.
>>
>> cheers
>>
>> chaals
>>
>> On Monday, Feb 10, 2003, at 22:21 Australia/Melbourne,
>> Scarlett Julian
>> (ED) wrote:
>>>
>>> Consider a hypothetical situation where a metatag with no
>> content is
>>> included in the page mark-up
>>>  e.g <meta name="foo" content="" />
>>>
>>> What implications will this have?
>> --
>> Charles McCathieNevile           charles@sidar.org
>> Fundación SIDAR                       http://www.sidar.org
>>
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--
Charles McCathieNevile           charles@sidar.org
Fundación SIDAR                       http://www.sidar.org
The information in this email is confidential. The contents may not be disclosed or used by anyone other than the addressee.  If you are not the addressee, please tell us by using the reply facility in your email software as soon as possible. Sheffield City Council cannot accept any responsibility for the accuracy or completeness of this message as it has been transmitted over a public network.  If you suspect that the message may have been intercepted or amended please tell us as soon as possible.
Received on Monday, 10 February 2003 10:55:49 GMT

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