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RE: BIDI IRI Display (was spoofing and IRIs)

From: Matitiahu Allouche <matial@il.ibm.com>
Date: Thu, 4 Mar 2010 11:49:51 +0200
To: Shawn Steele <Shawn.Steele@microsoft.com>
Cc: Larry Masinter <LMM@acm.org>, Peter Constable <petercon@microsoft.com>, "public-iri@w3.org" <public-iri@w3.org>, public-iri-request@w3.org, "'Slim Amamou'" <slim@alixsys.com>, "unicode@unicode.org" <unicode@unicode.org>
Message-ID: <OF53795D0F.BC1C8CD7-ONC22576DC.00333515-C22576DC.0036005A@il.ibm.com>
Unfortunately, usability studies are hard to set up and expensive to run.

I once conducted a very informal inquiry on about 20 persons, the majority 
not engineers but with experience in using computers. The inquiry was 
about e-mail addresses, not IRIs. The surprising (for me) result was that 
the majority favored laying out address parts consistently from left to 
right, even within a global RTL context.
For example, consider the following address (in logical order, with upper 
case letters representing letters from RTL scripts):
     "DAVE SMITH" <DAVE.SMITH@MY.MAIL.company.com>
According to the inquiry result, it should be displayed as follows:
     "HTIMS EVAD" <EVAD.HTIMS@YM.LIAM.company.com>
whether in a LTR or RTL context.

The Israel bureau of standards (SII) has adopted the same position, with a 
scope including in particular mail addresses, IRIs, file and path names.

As always, YMMV.

I consider this issue as related to usability much more than to security, 
but since it has been evoked on this list, the above information may shed 
light on one point of view.


Shalom (Regards),  Mati
           Bidi Architect
           Globalization Center Of Competency - Bidirectional Scripts
           IBM Israel
           Phone: +972 2 5888802    Fax: +972 2 5870333    Mobile: +972 52 
2554160




From:
Shawn Steele <Shawn.Steele@microsoft.com>
To:
Larry Masinter <LMM@acm.org>, "'Slim Amamou'" <slim@alixsys.com>
Cc:
"public-iri@w3.org" <public-iri@w3.org>, Peter Constable 
<petercon@microsoft.com>, "unicode@unicode.org" <unicode@unicode.org>
Date:
04/03/2010 07:57
Subject:
RE: BIDI IRI Display (was spoofing and IRIs)
Sent by:
public-iri-request@w3.org



The problem isn't an IRI in different contexts (a list of IRIs or not), 
the problem is that an IRI *IS* a list.

http://www.microsoft.com/en/us/default.aspx is a lot like { www, 
microsoft, com, en, us, default.aspx }, so IRI's shouldn't mix up the 
parts, (eg: reversing en & us in the display would be misleading).  In a 
BIDI context, this probably means that the elements of the list are 
ordered from right to left.  The problem with the Unicode bidi algorithm 
is that if 2 LTR script elements are adjacent, they lose the ordering of 
the list.

Users seem to expect that elements of an IRI are drawn as a list like I 
described.  It has also been proposed that they just be rendered from LTR 
regardless of whether any labels are RTL or not, and another suggestion 
has been that users don't really understand the ordering of the IRI, so 
it's okay to reorder as long as it's consistent. 

I would like to see a usability study to figure out what the average BIDI 
user expects since us engineers may have biases that most people don't 
have.  My informal observations and feedback from the BIDI community seems 
to support the "elements of a list" hypothesis, however I'd like that to 
be confirmed (or disproved) by a "real" usability study :)

-Shawn

________________________________________
From: Larry Masinter [masinter@gmail.com] on behalf of Larry Masinter 
[LMM@acm.org]
Sent: Wednesday, March 03, 2010 6:00 PM
To: Shawn Steele; 'Slim Amamou'
Cc: public-iri@w3.org; Peter Constable; unicode@unicode.org
Subject: RE: BIDI IRI Display (was spoofing and IRIs)

If the same Unicode string is used for an IRI in running text and for
an IRI in a context where its use as a "ordered list", then it would
seem like

* the presentation of the IRI in different contexts is the same

is more important than

* the presentation of the IRI in known IRI contexts is optimal

Do you agree? I don't see how you can have both.

Larry
--
http://larry.masinter.net


-----Original Message-----
From: Shawn Steele [mailto:Shawn.Steele@microsoft.com]
Sent: Wednesday, March 03, 2010 9:13 AM
To: Slim Amamou; Larry Masinter
Cc: public-iri@w3.org; Peter Constable; (unicode@unicode.org)
Subject: RE: BIDI IRI Display (was spoofing and IRIs)

> An IRI is a sequence of Unicode characters. Is there not
> already a well-defined way of converting a sequence of
> Unicode characters to a visual display?

The problem (from my perspective at least) is that the Unicode BIDI
rules are somewhat "generic".  Unicode expects things like / and . to
be used in a context of same-script stuff, like a date, time or
number.  IRIs use them as delimiters for a list of elements (labels in
the domain name or folders in the path), in a hierarchical form.  The
Unicode BIDI algorithm doesn't recognize that there's an underlying
hierarchy, so it can end up "swapping" pieces in that hierarchy in
some cases.

I'm not sure UTR#36 is the proper place to clarify display of such
ordered lists.  Proper BIDI rendering of IRIs isn't just a security,
but also a usability, problem.  It does seem like perhaps this concept
should be mentioned in Unicode somewhere.  (IRIs aren't the only place
that similar ordered lists happen).

-Shawn
Received on Thursday, 4 March 2010 09:50:33 UTC

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