using the Public Suffix list

On a number of occasions I have wanted to decompose domain names, for example in the URL recogniser in Snip!t.  However, one problem has always been the bit at the end.  It is clear that ‘com’ and ‘ac.uk’ are the principle suffixes of ‘www.alandix.com’ and ‘www.cs.bham.ac.uk’ respectively.  However, while I know that for UK domains it is the last two components that are important (second level domains), I never knew how to work this out in general for other countries.  Happily, Mozilla and other browser vendors have an initiative called the Public Suffix List , which provides a list of just these important critical second level (and deeper level) suffixes.

I recently found I needed this again as part of my Talis research.  There is a Ruby library and a Java sourceforge project for reading the Public Suffix list, and an implementation by the DKIM Reputation project, that transforms the list into generated tables for C, PHP and Perl.  However, nothing for easily and automatically maintaining access to the list.  So I have written a small PHP class to parse, store and access the Public Suffix list. There is an example in the public suffix section of the ‘code’ pages in this blog, and it also has its own microsite including more examples, documentation and a live demo to try.

Web Art/Science Camp — how web killed the hypertext star and other stories

Had a great day on Saturday at the at the Web Art/Science Camp (twitter: #webartsci , lanyrd: web-art-science-camp). It was the first event that I went to primarily with my Talis hat on and first Web Science event, so very pleased that Clare Hooper told me about it during the DESIRE Summer School.

The event started on Friday night with a lovely meal in the restaurant at the British Museum. The museum was partially closed in the evening, but in the open galleries Rosetta Stone, Elgin Marbles and a couple of enormous totem poles all very impressive. … and I notice the BM’s website when it describes the Parthenon Sculptures does not waste the opportunity to tell us why they should not be returned to Greece!

Treasury of Atreus

I was fascinated too by images of the “Treasury of Atreus” (which is actually a Greek tomb and also known as the Tomb of Agamemnon. The tomb has a corbelled arch (triangular stepped stones, as visible in the photo) in order to relieve load on the lintel. However, whilst the corbelled arch was an important technological innovation, the aesthetics of the time meant they covered up the triangular opening with thin slabs of fascia stone and made it look as though lintel was actually supporting the wall above — rather like modern concrete buildings with decorative classical columns.

how web killed the hypertext star

On Saturday, the camp proper started with Paul de Bra from TU/e giving a sort of retrospective on pre-web hypertext research and whether there is any need for hypertext research anymore. The talk brought out several of the issues that have worried me also for some time; so many of the lessons of the early hypertext lost in the web1.

For me one of the most significant issues is external linkage. HTML embeds links in the document using <a> anchor tags, so that only the links that the author has thought of can be present (and only one link per anchor). In contrast, mature pre-web hypertext systems, such as Microcosm2, specified links eternally to the document, so that third parties could add annotation and links. I had a few great chats about this with one of the Southampton Web Science DTC students; in particular, about whether Google or Wikipedia effectively provide all the external links one needs.

Paul’s brief history of hypertext started, predictably, with Vannevar Bush‘s  “As We May Think” and Memex; however he pointed out that Bush’s vision was based on associative connections (like the human mind) and trails (a form of narrative), not pairwise hypertext links. The latter reminded me of Nick Hammond’s bus tour metaphor for guided educational hypertext in the 1980s — occasionally since I have seen things a little like this, and indeed narrative was an issue that arose in different guises throughout the day.

While Bush’s trails are at least related to the links of later hypertext and the web, the idea of associative connections seem to have been virtually forgotten.  More recently in the web however, IR (information retrieval) based approaches for page suggestions like Alexa and content-based social networking have elements of associative linking as does the use of spreading activation in web contexts3

It was of course Nelson who coined the term hypertext, but Paul reminded us that Ted Nelson’s vision of hypertext in Xanadu is far richer than the current web.  As well as external linkage (and indeed more complex forms in his ZigZag structures, a form of faceted navigation.), Xanadu’s linking was often in the form of transclusions pieces of one document appearing, quoted, in another. Nelson was particularly keen on having only one copy of anything, hence the transclusion is not so much a copy as a reference to a portion. The idea of having exactly one copy seems a bit of computing obsession, and in non-technical writing it is common to have quotations that are in some way edited (elision, emphasis), but the core thing to me seems to be the fact that the target of a link as well as the source need not be the whole document, but some fragment.

Paul de Bra's keynote at Web Art/Science Camp (photo Clare Hooper)

Over a period 30 years hypertext developed and started to mature … until in the early 1990s came the web and so much of hypertext died with its birth … I guess a bit like the way Java all but stiltified programming languages. Paul had a lovely list of bad things about the web compared with (1990s) state of the art hypertext:

Key properties/limitations in the basic Web:

  1. uni-directional links between single nodes
  2. links are not objects (have no properties of their own)
  3. links are hardwired to their source anchor
  4. only pre-authored link destinations are possible
  5. monolithic browser
  6. static content, limited dynamic content through CGI
  7. links can break
  8. no transclusion of text, only of images

Note that 1, 3 and 4 are all connected with the way that HTML embeds links in pages rather than adopting some form of external linkage. However, 2 is also interesting; the fact that links are not ‘first class objects’. This has been preserved in the semantic web where an RDF triple is not itself easily referenced (except by complex ‘reification’) and so it is hard to add information about relationships such as provenance.

Of course, this same simplicity (or even that it was simplistic) that reduced the expressivity of HTML compared with earlier hypertext is also the reasons for its success compared with earlier more heavy weight and usually centralised solutions.

However, Paul went on to describe how many of the features that were lost have re-emerged in plugins, server enhancements (this made me think of systems such as zLinks, which start to add an element of external linkage). I wasn’t totally convinced as these features are still largely in research prototypes and not entered the mainstream, but it made a good end to the story!

demos and documentation

There was a demo session as well as some short demos as part of talks. Lots’s of interesting ideas. One that particularly caught my eye (although not incredibly webby) was Ana Nelson‘s documentation generator “dexy” (not to be confused with doxygen, another documentation generator). Dexy allows you to include code and output, including screen shots, in documentation (LaTeX, HTML, even Word if you work a little) and live updates the documentation as the code updates (at least updates the code and output, you need to change the words!). It seems to be both a test harness and multi-version documentation compiler all in one!

I recall that many years ago, while he was still at York, Harold Thimbleby was doing something a little similar when he was working on his C version of Knuth’s WEB literate programming system. Ana’s system is language neutral and takes advantage of recent developments, in particular the use of VMs to be able to test install scripts and to be sure to run code in a consistent environments. Also it can use browser automation for web docs — very cool 🙂

Relating back to Paul’s keynote this is exactly an example of Nelson’s transclusion — the code and outputs included in the document but still tied to their original source.

And on this same theme I demoed Snip!t as an example of both:

  1. attempting to bookmark parts of web pages, a form of transclusion
  2. using data detectors a form of external linkage

Another talk/demo also showed how Compendium could be used to annotate video (in the talk regarding fashion design) and build rationale around … yet another example of external linkage in action.

… and when looking after the event at some of Weigang Wang‘s work on collaborative hypermedia it was pleasing to see that it uses a theoretical framework for shared understanding in collaboratuve hypermedia that builds upon my own CSCW framework from the early 1990s 🙂

sessions: narrative, creativity and the absurd

Impossible to capture in a few words, but one session included different talks and discussion about the relation of narrative and various forms of web experiences — including a talk on the cognitive psychology of the Kafkaesque. Also discussion of creativity with Nathan live recording in IBIS!

what is web science

I guess inevitably in a new area there was some discussion about “what is web science” and even “is web science a discipline”. I recall similar discussions about the nature of HCI 25 years ago and not entirely resolved today … and, as an artist who was there reminded us, they still struggle with “what is art?”!

Whether or not there is a well defined discipline of ‘web science’, the web definitely throws up new issues for many disciplines including new challenges for computing in terms of scale, and new opportunities for the social sciences in terms of intrinsically documented social interactions. One of the themes that recurred to distinguish web science from simply web technology is the human element — joy to my ears of course as a HCI man, but I think maybe not the whole story.

Certainly the gathering of people from different backgrounds in a sort of disciplinary bohemia is exciting whether or not it has a definition.

  1. see also “Names, URIs and why the web discards 50 years of computing experience“[back]
  2. Wendy Hall, Hugh Davis and Gerard Hutchings, “Rethinking Hypermedia:: The Microcosm Approach, Springer, 1996.[back]
  3. Spreading activation is used by a number of people, some of my own work with others at Athens, Rome and Talis is reported in “Ontologies and the Brain: Using Spreading Activation through Ontologies to Support Personal Interaction” and “Spreading Activation Over Ontology-Based Resources: From Personal Context To Web Scale Reasoning“.[back]

Names, URIs and why the web discards 50 years of computing experience

Names and naming have always been a big issue both in computer science and philosophy, and a topic I have posted on before (see “names – a file by any other name“).

In computer science, and in particular programming languages, a whole vocabulary has arisen to talk about names: scope, binding, referential transparency. As in philosophy, it is typically the association between a name and its ‘meaning’ that is of interest. Names and words, whether in programming languages or day-to-day language, are, what philosophers call, ‘intentional‘: they refer to something else. In computer science the ‘something else’ is typically some data or code or a placeholder/variable containing data or code, and the key question of semantics or ‘meaning’ is about how to identify which variable, function or piece of data a name refers to in a particular context at a particular time.

The emphasis in computing has tended to be about:

(a) Making sure names have unambiguous meaning when looking locally inside code. Concerns such as referential transparency, avoiding dynamic binding and the deprecation of global variables are about this.

(b) Putting boundaries on where names can be seen/understood, both as a means to ensure (a) and also as part of encapsulation of semantics in object-based languages and abstract data types.

However, there has always been a tension between clarity of intention (in both the normal and philosophical sense) and abstraction/reuse. If names are totally unambiguous then it becomes impossible to say general things. Without a level of controlled ambiguity in language a legal statement such as “if a driver exceeds the speed limit they will be fined” would need to be stated separately for every citizen. Similarly in computing when we write:

function f(x) { return (x+1)*(x-1); }

The meaning of x is different when we use it in ‘f(2)’ or ‘f(3)’ and must be so to allow ‘f’ to be used generically. Crucially there is no internal ambiguity, the two ‘x’s refer to the same thing in a particular invocation of ‘f’, but the precise meaning of ‘x’ for each invocation is achieved by external binding (the argument list ‘(2)’).

Come the web and URLs and URIs.

Fiona@lovefibre was recently making a test copy of a website built using WordPress. In a pure html website, this is easy (so long as you have used relative or site-relative links within the site), you just copy the files and put them in the new location and they work 🙂 Occasionally a more dynamic site does need to know its global name (URL), for example if you want to send a link in an email, but this can usually be achieved using configuration file. For example, there is a development version of Snip!t at cardiff.snip!t.org (rather then www.snipit.org), and there is just one configuration file that needs to be changed between this test site and the live one.

Similarly in a pristine WordPress install there is just such a configuration file and one or two database entries. However, as soon as it has been used to create a site, the database content becomes filled with URLs. Some are in clear locations, but many are embedded within HTML fields or serialised plugin options. Copying and moving the database requires a series of SQL updates with string replacements matching the old site name and replacing it with the new — both tedious and needing extreme care not to corrupt the database in the process.

Is this just a case of WordPress being poorly engineered?

In fact I feel more a problem endemic in the web and driven largely by the URL.

Recently I was experimenting with Firefox extensions. Being a good 21st century programmer I simply found an existing extension that was roughly similar to what I was after and started to alter it. First of course I changed its name and then found I needed to make changes through pretty much every file in the extension as the knowledge of the extension name seemed to permeate to the lowest level of the code. To be fair XUL has mechanisms to achieve a level of encapsulation introducing local URIs through the ‘chrome:’ naming scheme and having been through the process once. I maybe understand a bit better how to design extensions to make them less reliant on the external name, and also which names need to be changed and which are more like the ‘x’ in the ‘f(x)’ example. However, despite this, the experience was so different to the levels of encapsulation I have learnt to take for granted in traditional programming.

Much of the trouble resides with the URL. Going back to the two issues of naming, the URL focuses strongly on (a) making the name unambiguous by having a single universal namespace;  URLs are a bit like saying “let’s not just refer to ‘Alan’, but ‘the person with UK National Insurance Number XXXX’ so we know precisely who we are talking about”. Of course this focus on uniqueness of naming has a consequential impact on generality and abstraction. There are many visitors on Tiree over the summer and maybe one day I meet one at the shop and then a few days later pass the same person out walking; I don’t need to know the persons NI number or URL in order to say it was the same person.

Back to Snip!t, over the summer I spent some time working on the XML-based extension mechanism. As soon as these became even slightly complex I found URLs sneaking in, just like the WordPress database 🙁 The use of namespaces in the XML file can reduce this by at least limiting full URLs to the XML header, but, still, embedded in every XML file are un-abstracted references … and my pride in keeping the test site and live site near identical was severely dented1.

In the years when the web was coming into being the Hypertext community had been reflecting on more than 30 years of practical experience, embodied particularly in the Dexter Model2. The Dexter model and some systems, such as Wendy Hall’s Microcosm3, incorporated external linkage; that is, the body of content had marked hot spots, but the association of these hot spots to other resources was in a separate external layer.

Sadly HTML opted for internal links in anchor and image tags in order to make html files self-contained, a pattern replicated across web technologies such as XML and RDF. At a practical level this is (i) why it is hard to have a single anchor link to multiple things, as was common in early Hypertext systems such as Intermedia, and (ii), as Fiona found, a real pain for maintenance!

  1. I actually resolved this by a nasty ‘hack’ of having internal functions alias the full site name when encountered and treating them as if they refer to the test site — very cludgy![back]
  2. Halasz, F. and Schwartz, M. 1994. The Dexter hypertext reference model. Commun. ACM 37, 2 (Feb. 1994), 30-39. DOI= http://doi.acm.org/10.1145/175235.175237[back]
  3. Hall, W., Davis, H., and Hutchings, G. 1996 Rethinking Hypermedia: the Microcosm Approach. Kluwer Academic Publishers.[back]

Apache: pretty URLs and rewrite loops

[another techie post – a problem I had and can see that other people have had too]

It is common in various web frameworks to pass pretty much everything through a central script using Apache .htaccess file and mod_rewrite.  For example enabling permalinks in a WordPress blog generates an .htaccess file like this:

RewriteEngine On
RewriteBase /blog/
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /blog/index.php [L]

I use similar patterns for various sites such as vfridge (see recent post “Phoenix rises“) and Snip!t.  For Snip!t however I was using not a local .htaccess file, but an AliasMatch in httpd.conf, which meant I needed to ask Fiona every time I needed to do a change (as I can never remember the root passwords!).  It seemed easier (even if slightly less efficient) to move this to a local .htaccess file:

RewriteEngine On
RewriteBase /
RewriteRule ^(.*)$ code/top.php/$1 [L]

The intention is to map “/an/example?args” into “/code/top.php/an/example?args”.

Unfortunately this resulted in a “500 internal server error” page and in the Apache error log messages saying there were too many internal redirects.  This seems to be a common problem reported in forums (see here, here and here).  The reason for this is that .htaccess files are encountered very late in Apache’s processing and so anything rewritten by the rules gets thrown back into Apache’s processing almost as if they were a fresh request.  While the “[L]”(last)  flags says “don’t execute any more rules”, this means “no more rules on this pass”, but when Apache gets back to the .htaccess in the fresh round the rule gets encountered again and again leading to an infinite loop “/code/top/php/code/top.php/…/code/top.php/an/example?args”.

Happily, mod_rewrite thought of this and there is an additional “[NS]” (nosubreq) flag that says “only use this rule on the first pass”.  The mod_rewrite documentation for RewriteRule in Apache 1.3, 2.0 and 2.3 says:

Use the following rule for your decision: whenever you prefix some URLs with CGI-scripts to force them to be processed by the CGI-script, the chance is high that you will run into problems (or even overhead) on sub-requests. In these cases, use this flag.

I duly added the flag:

RewriteRule ^(.*)$ code/top.php/$1 [L,NS]

This should work, but doesn’t.  I’m not sure why except that the Apache 2.2 documentation for NS|nosubreq reads:

NS|nosubreq

Use of the [NS] flag prevents the rule from being used on subrequests. For example, a page which is included using an SSI (Server Side Include) is a subrequest, and you may want to avoid rewrites happening on those subrequests.

Images, javascript files, or css files, loaded as part of an HTML page, are not subrequests – the browser requests them as separate HTTP requests.

This is identical to the documentation for 1.3, 2.0 and 2.3 except that quote about “URLs with CGI-scripts” is singularly missing.  I can’t find anything that says so, but my guess is that there was some bug (feature?) introduced 2.2 that is being fixed in 2.3.

WordPress is immune from the infinite loop as the directive “RewriteCond %{REQUEST_FILENAME} !-f” says “if the file exists use that without rewriting”.  As “index.php” is a file, the rule does not rewrite a second time.  However, the layout of my files meant that I sometimes have an actual file in the pseudo location (e.g. /an/example really exists).  I could have reorganised the complete directory structure … but then I would have been still fixing all the broken links now!

Instead I simply added an explicit “please don’t rewrite my top.php script” condition:

RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_URI}  !^/code/top.php/.*
RewriteRule ^(.*)$ code/top.php/$1 [L,NS]

I suspect that this will be unnecessary when Apache upgrades to 2.3, but for now … it works 🙂

Italian conferences: PPD10, AVI2010 and Search Computing

I got back from trip to Rome and Milan last Tuesday, this included the PPD10 workshop that Aaron, Lucia, Sri and I had organised, and the AVI 2008 conference, both in University of Rome “La Sapienza”, and a day workshop on Search Computing at Milan Polytechnic.

PPD10

The PPD10 workshop on Coupled Display Visual Interfaces1 followed on from a previous event, PPD08 at AVI 2008 and also a workshop on “Designing And Evaluating Mobile Phone-Based Interaction With Public Displays” at CHI2008.  The linking of public and private displays is something I’ve been interested in for some years and it was exciting to see some of the kinds of scenarios discussed at Lancaster as potential futures some years ago now being implemented over a range of technologies.  Many of the key issues and problems proposed then are still to be resolved and new ones arising, but certainly it seems the technology is ‘coming of age’.  As well as much work filling in the space of interactions, there were also papers that pushed some of the existing dimensions/classifications, in particular, Rasmus Gude’s paper on “Digital Hospitality” stretched the public/private dimension by considering the appropriation of technology in the home by house guests.  The full proceedings are available at the PPD10 website.

AVI 2010

AVI is always a joy, and AVI 2010 no exception; a biennial, single-track conference with high-quality papers (20% accept rate this year), and always in lovely places in Italy with good food and good company!  I first went to AVI in 1996 when it was in Gubbio to give a keynote “Closing the Loop: modelling action, perception and information“, and have gone every time since — I always say that Stefano Levialdi is a bit like a drug pusher, the first experience for free and ever after you are hooked! The high spot this year was undoubtedly Hitomi Tsujita‘s “Complete fashion coordinator2, a system for using social networking to help choose clothes to wear — partly just fun with a wonderful video, but also a very thoughtful mix of physical and digital technology.


images from Complete Fashion Coordinator

The keynotes were all great, Daniel Keim gave a really lucid state of the art in Visual Analytics (more later) and Patrick Lynch a fresh view of visual understanding based on many years experience and highlighting particularly on some of the more immediate ‘gut’ reactions we have to interfaces.  Daniel Wigdor gave an almost blow-by-blow account of work at Microsoft on developing interaction methods for next-generation touch-based user interfaces.  His paper is a great methodological exemplar for researchers combining very practical considerations, more principled design space analysis and targeted experimentation.

Looking more at the detail of Daniel’s work at Microsoft, it is interesting that he has a harder job than Apple’s interaction developers.  While Apple can design the hardware and interaction together, MS as system providers need to deal with very diverse hardware, leading to a ‘least common denominator’ approach at the level of quite basic touch interactions.  For walk-up-and use systems such as Microsoft Surface in bar tables, this means that users have a consistent experience across devices.  However, I did wonder whether this approach which is basically the presentation/lexical level of Seeheim was best, or whether it would be better to settle at some higher-level primitives more at the Seeheim dialog level, thinking particularly of the way the iPhone turns pull down menus form web pages into spinning selectors.  For devices that people own it maybe that these more device specific variants of common logical interactions allow a richer user experience.

The complete AVI 2010 proceedings (in colour or B&W) can be found at the conference website.

The very last session of AVI was a panel I chaired on “Visual Analytics: people at the heart of data” with Daniel Keim, Margit Pohl, Bob Spence and Enrico Bertini (in the order they sat at the table!).  The panel was prompted largely because the EU VisMaster Coordinated Action is producing a roadmap document looking at future challenges for visual analytics research in Europe and elsewhere.  I had been worried that it could be a bit dead at 5pm on the last day of the conference, but it was a lively discussion … and Bob served well as the enthusiastic but also slightly sceptical outsider to VisMaster!

As I write this, there is still time (just, literally weeks!) for final input into the VisMaster roadmap and if you would like a draft I’ll be happy to send you a PDF and even happier if you give some feedback 🙂

Search Computing

I was invited to go to this one-day workshop and had the joy to travel up on the train from Rome with Stu Card and his daughter Gwyneth.

The search computing workshop was organised by the SeCo project. This is a large single-site project (around 25 people for 5 years) funded as one of the EU’s ‘IDEAS Advanced Grants’ supporting ‘investigation-driven frontier research’.  Really good to see the EU funding work at the bleeding edge as so many national and European projects end up being ‘safe’.

The term search computing was entirely new to me, although instantly brought several concepts to mind.  In fact the principle focus of SeCo is the bringing together of information in deep web resources including combining result rankings; in database terms a form of distributed join over heterogeneous data sources.

The work had many personal connections including work on concept classification using ODP data dating back to aQtive days as well as onCue itself and Snip!t.  It also has similarities with linked data in the semantic web word, however with crucial differences.  SeCo’s service approach uses meta-descriptions of the services to add semantics, whereas linked data in principle includes a degree of semantics in the RDF data.  Also the ‘join’ on services is on values and so uses a degree of run-time identity matching (Stu Card’s example was how to know that LA=’Los Angeles’), whereas linked data relies on URIs so (again in principle) matching has already been done during data preparation.  My feeling is that the linking of the two paradigms would be very powerful, and even for certain kinds of raw data, such as tables, external semantics seems sensible.

One of the real opportunities for both is to harness user interaction with data as an extra source of semantics.  For example, for the identity matching issue, if a user is linking two data sources and notices that ‘LA’ and ‘Los Angeles’ are not identified, this can be added as part of the interaction to serve the user’s own purposes at that time, but by so doing adding a special case that can be used for the benefit of future users.

While SeCo is predominantly focused on the search federation, the broader issue of using search as part of algorithmics is also fascinating.  Traditional algorithmics assumes that knowledge is basically in code or rules and is applied to data.  In contrast we are seeing the rise of web algorithmics where knowledge is garnered from vast volumes of data.  For example, Gianluca Demartini at the workshop mentioned that his group had used the Google suggest API to extend keywords and I’ve seen the same trick used previously3.  To some extent this is like classic techniques of information retrieval, but whereas IR is principally focused on a closed document set, here the document set is being used to establish knowledge that can be used elsewhere.  In work I’ve been involved with, both the concept classification and folksonomy mining with Alessio apply this same broad principle.

The slides from the workshop are appearing (but not all there yet!) at the workshop web page on the SeCo site.

  1. yes I know this doesn’t give ‘PPD’ this stands for “public and private displays”[back]
  2. Hitomi Tsujita, Koji Tsukada, Keisuke Kambara, Itiro Siio, Complete Fashion Coordinator: A support system for capturing and selecting daily clothes with social network, Proceedings of the Working Conference on Advanced Visual Interfaces (AVI2010), pp.127–132.[back]
  3. The Yahoo! Related Suggestions API offers a similar service.[back]

Recognition vs classification

While putting away the cutlery I noticed that I always do it one kind at a time: all the knives, then all the forks, etc. While this may simply be a sign of an obsessive personality, I realised there was a general psychological principle at work here.

We often make the distinction between recognition and recall and know, as interface designers, that the former is easier, especially for infrequently used features, e.g. menus rather than commands.

In the cutlery tray task the trade-off is between a classification task “here is an item what kind is it?” versus a visual recognition one “where is the next knife”. The former requires a level of mental processing and is subject to Hick’s law, whereas the latter depends purely on lower level visual processing, a pop-out effect.

I am wondering whether this has user interface equivalents. I am thinking about times when one is sorting things: bookmarks, photos, even my own snip!t. Sometimes you work by classification: select an item, then choose where to put it; for others you choose a category (or an album) and then select what to put in it. Here the ‘recognition’ task is more complex and not just visual, but I wonder if the same principle applies?

Sounds like a good dissertation project!

Firefox 3 seems to have fixed memory problems

I had been reluctantly considering giving up using Firefox as it crawled to a halt so often on so many sites. To be fair I think it is because I keep lots of tabs open and Firefox did not seem to deal will with pages with many refreshing elements … many air and train ticketing sites were particular problems. However, Firefox 3 has been running continuously for some time now and looking at ‘top’ in terminal window has about 1/3 the real memory footprint compared with Firefox 2 … now it is comparable with Word, Dreamweaver, etc. … I had been sticking with Firefox largely because the Firefox Snip!t bookmarklet works better than the Safari one, so now I can continue to do so without the machine crawling to a halt – well done team Mozilla 🙂

local URIs … mashing up the desktop

I’ve worried for a while about desktop URLs.

Within the web it is easy to link things together. If I want to refer to my home page I just add a link like this. However, on the desktop things are not so simple and I end up copying chunks of mail messages into the notes field in iCal rather than simply being able to link to the mail message where I arranged the meeting.

Links from the desktop to the web are easy … just use the URL … many desktop applications including mail clients and word processors will allow you to embed clickable links. Indeed it is often easier to link to a web page than to another object on the desktop! However, things get more difficult if you want to link the other way round, from a web page to a local file or resource. In my browser’s favourites I have several links to local files, but you cannot easily do the same if your bookmarks are in a web service like del.icio.us or even my own Snip!t. It is hard to seamlessly weave your desktop into the global web.

A couple of events brought this issue to a head for me.

First at the CHI workshop on PIM entitled the Disappearing Desktop, I asked if anyone knew of work in the area and I heard from Leo Sauermann that they had made some progress on this as part of the Gnowsis project. Their proposal for a Desktop URI Scheme (edited by Leo) is targeted principally at the first of the scenarios above, being able to link between things within the desktop.

The second event was at the AVI workshop on designing multi-touch interaction techniques for coupled public and private displays. During discussions abut touch-based interactions such as the Microsoft Surface or Apple iPhone, we considered scenarios where peole got together for a meeting (as we were) in a hotel bar (where we split for small group discussion) and had screens on table tops and walls, laptops, tablets, phones … and wanted to seamlessly move material between devices. Clearly an essential requirement for which is some way to identify resources across ad hoc collections of devices.

Finally I was in Athens working with George Lepouras, Akrivi Katifori and others. George had developed a Thunderbird extension to allow Snip!t to snip from mail messages … but while we could snip the text there was no way for the Snip!t page to link back to the mail message. We need full round trip URIs that link desktop and web with no distinction – URIs that can be embedded in a web page and (assuming you have the right permissions and are in an appropriate place) can be clicked and the appropriate mail message, calendar entry or whatever is opened.

Based on this and discussions we had, I drafted a discussion document on globally accessible local URIs. Any feedback very welcome.

Over the summer we hope to put together a demonstrator / reference implementation – if anyone is interested let me know.

mobile design workshop

A couple of weeks ago I attended a mobile design workshop at microsoft labs in Cambridge. Great 2 days … people from academia and industry (and no not just MS, also Google, Yahoo, Sony, Nokia, …!)
Alan in Helmet

Most of the time was spent splitting into small working groups then coming back together for plenaries. I took part in groups discussing:

(1) tools to make it easier for those in developing countries to design mobile phone applications that suit their needs [session notes], rather than simply passing on applications and designs fitted for very different needs and infrastructure. During the discussion various applications of phone technology were cited that were completely different form those we would expect in the UK, US or Europe, but fitted the situations of people. These included using the address book as a ‘who owes what’ list for a trader … the ‘telephone numbers’ were in act amounts of money! This use of ‘ancillary’ parts of the phone rather than simply being a glorified communication device. Although he context of this was Africa, it also echoes studies of domestic phone use by Malay women in the UK by Fariza (who has just had her PhD viva :-)). She found alarm, calculator and things like that, at least as important as phone & text for the people she studied.

(2) ‘mindfulness’ and mobile phones … and of course the fact that normally they do the opposite interupting etc. … but just to not make us all agree too much, I said that mindfulness sounded like we should all become like rabbits; it is the looking forward and back, with all its stress, that is one of the things that make us human.

(3) task/data oriented interaction … escaping from the ‘application’. This was particularly relevant to me given onCue at aQtive was in this space as are Snip!t and work on TIM project with colleagues at Rome, Athens and recently new collaborators Madrid … with whom I had a short but lovely visit after CHI.

Task session

I just wanted to print a file

I just wanted to print a file, now it is an hour and a half later and I still have nothing … this is where all our time goes gently coaxing our computers in the hope they may do what we ask.

Such a simple thing to want to do … and so much pain on the process, and so many simple things that application designers could do it make it better.

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