Alan’s blog

Naming things seems relatively unproblematic until you try to do it — ask any couple with a baby on the way.  Naming files is no easier.

Earlier today Fiona @lovefibre was using the MAC OS Time Machine to retrieve an old version of a file (let’s call it “fisfile.doc”).  She wanted to extract a part that she knew she had deleted in order to use in the current version.  Of course the file you are retrieving has the same name as the current file, and the default is to overwrite the current version; that is a simple backup restore.  However, you can ask Time Machine to retain both versions; at which point you end up with two files called, for example, “fisfile.doc” and “fisfile-original.doc”.  In this case ‘original’ means ‘the most recent version’ and the unlabelled one is the old version you have just restored.  This was not  too confusing, but personally I would have been tempted to call the restored file something like “fisfile-2010-01-17-10-33.doc”, in particular because one wonders what will happen if you try to restore several copies of the same file to work on, for example, to work out when an error slipped into a document.

OK, just an single incident, but only a few minutes later I had another example of problematic naming.

(more…)

I was wondering about scanning barcodes using the iPhone and found that pic2shop (a free app) lets third part iPhone apps and even web pages access its scanning software through a simply URL scheme interface.

Their developer documentation has an example iPhone app, but not an example web page.  However, I made a web page using their interface in about 5 minutes (see PHP source of barcode reader).

If you have an iPhone you can try it out and scan a bar code now, although you need to install pic2shop first (but it is free).

By allowing third party apps to use their software they encourage downloads of their app, which will bring them revenue through product purchases.  Through free giving they bring themselves benefit; a good open access story.

Encountered the following when downloading a file for proof checking from the Elsevier “E-Proofing” System web site¹.  Happily it turned out to be a mere 950 K not a gigabyte!

1. I was going to add a link to the system web site itself at http://elsevier.sps.co.in/ but instead of some sort of home page you get redirected to the proofs of someone’s article in the Journal of Computational Physics! [back]

After following a link from one of Nad’s tweets, read Jeni Tennison’s “SPARQL & Visualisation Frustrations: RDF Datatyping“.  Jeni had been having problems processing RDF of MP’s expense claims, because the amounts were plain RDF strings rather than as typed numbers.  She  suggests some best practice rules for data types in RDF based on the underlying philosophy of RDF that it should be self-describing:

• if the literal is XML, it should be an XML literal
• if the literal is in a particular language (such as a description or a name), it should be a plain literal with that language
• otherwise it should be given an appropriate datatype

These seem pretty sensible for simple data types.

In work on the TIM project with colleagues in Athens and Rome, we too had issues with representing data types in ontologies, but more to do with the status of a data type.  Is a date a single thing “2009-08-03T10:23+01:00″, or is it a compound [[date year="2009" month="8" ...]]?

I just took a quick peek at how Dublin Core handles dates and see that the closest to standard references¹ still include dates as ‘bare’ strings with implied semantics only, although one of the most recent docs does say:

“It is recommended that RDF applications use explicit rdf:type triples …”

and David MComb’s “An OWL version of the Dublin Core” gives an alternative OWL ontology for DC that does include an explicit type for dc:date:

<owl:DatatypeProperty rdf:about="#date">
  <rdfs:domain rdf:resource="#Document"/>
  <rdfs:range rdf:resource="http://www.w3.org/2001/XMLSchema#dateTime"/>
</owl:DatatypeProperty>

Our solution to the compound types has been to have “value classes” which do not represent ‘things’ in the world, similar to the way the RDF for vcard represents  complex elements such as names using blank nodes:

<vCard:N rdf:parseType="Resource">
  <vCard:Family> Crystal </vCard:Family>
  <vCard:Given> Corky </vCard:Given>
  ...
</vCard:N>

From²

This is fine, and we can have rules for parsing and formatting dates as compound objects to and from, say, W3C datetime strings.  However, this conflicts with the desire to have self-describing RDF as these formatting and parsing rules have to be available to any application or be present as reasoning rules in RDF stores.  If Jeni had been trying to use RDF data coded like this she would be cursing us!

This tension between representations of things (dates, names) and more semantic descriptions is also evident in other areas.  Looking again at Dublin Core the metamodal allows a property such as “subject”  to have a complex object with a URI and possibly several string values.

Very semantic, but hardly mashes well with sources that just say <dc:subject>Biology</dc:subject>.  Again a reasoning store could infer one from the other, but we still have issues about where the knowledge for such transformations resides.

Part of the problem is that the ’self-describing’ nature of RDF is a bit illusary.   In (Piercian) semiotics the interpretant of a sign is crucial, representations are interpreted by an agent in a particular context assuming a particular language, etc.  We do not expect human language to be ’sef describing’ in the sense of being totally acontextual.  Similarly in philosophy words and ideas are treated as intentional, in the (not standard English) sense that they refer out to something else; however, the binding of the idea to the thing it refers to is not part of the word, but separate from it.  Effectively the desire to be self-describing runs the risk of ignoring this distinction³.

Leigh Dodds commented on Jeni’s post to explain that the reason the expense amounts were not numbers was that some were published in non-standard ways such as “12345 (2004)”.  As an example this captures succinctly the perpetual problem between representation and abstracted meaning.  If a journal article was printed in the “Autumn 2007″ issue of  quarterly magazine, do we express this as <dc:date>2007</dc:date> or <dc:date>2007-10-01</dc:date>  attempting to give an approximation or inference from the actual represented date.

This makes one wonder whether what is really needed here is a meta-description of the RDF source (not simply the OWL as one wants to talk about the use of dc:date or whatever in a particular context) that can say things like “mainly numbers, but also occasionally non-strandard forms”, or “amounts sometimes refer to different years”.  Of course to be machine mashable there would need to be an ontology for such annotation …

1. see “Expressing Simple Dublin Core in RDF/XML“, “Expressing Dublin Core metadata using HTML/XHTML meta and link elements” and Stanford DC OWL [back]
2. Renato Iannella, Representing vCard Objects in RDF/XML, W3C Note, 22 February 2001. [back]
3. Doing a quick web seek, these issues are discussed in several places, for example: Glaser, H., Lewy, T., Millard, I. and Dowling, B. (2007) On Coreference and the Semantic Web, (Technical Report, Electronics & Computer Science, University of Southampton) and Legg, C. (2007). Peirce, meaning and the semantic web (Paper presented at Applying Peirce Conference, University of Helsinki, Finland, June 2007). [back]

Dynamic scoping/binding of variables has a bad name, rather like GOTO and other remnants of the Bad Old Days before Structured Programming saved us all¹.  But there are times when dynamic binding is useful and looking around it is very common in web scripting languages, event propagation, meta-level programming, and document styles.

So is it really so bad?

(more…)

1. Strangely also the days when major advances in substance seemed to be more important than minor advances in nomenclature [back]

Fiona @ lovefibre and I have often discussed the worrying decline of language used in many comments and postings on the web. Sometimes people are using compressed txtng language or even leetspeak, both of these are reasonable alternative codes to ‘proper’ English, and potentially part of the natural growth of the language.  However, it is often clear that the cause is ignorance not choice.  One of the reasons may be that many more people are getting a voice on the Internet; it is not just the journalists, academics and professional classes.  If so, this could be a positive social sign indicating that a public voice is no longer restricted to university graduates, who, of course, know their grammar perfectly …

Earlier today I was using Google to look up the author of a book I was reading and one of the top links was a listing on ratemyprofessors.com.  For interest I clicked through and saw:

“He sucks.. hes mean and way to demanding if u wanan work your ass off for a C+ take his class¹”

Hmm I wonder what this student’s course assignment looked like?

(more…)

1. In case you think I’m a complete pedant, personally, I am happy with both the slang ’sucks’ and ‘ass’ (instead of ‘arse’!), and the compressed speech ‘u’. These could be well-considered choices in language. The mistyped ‘wanna’ is also just a slip. It is the slightly more proper “hes mean and way to demanding” that seems to show  general lack of understanding.  Happily, the other comments, were not as bad as this one, but I did find the student who wanted a “descent grade” amusing [back]

I’m wondering why people break things when they create new versions.

Firefox used to open a discreet little window when you downloaded papers.  Now-a-days it opens a full screen window completely hiding the browser.

A minor issue, but makes me wonder about both new versions and also defaults and personalisation in general.

(more…)

You would think crash reporting would be made as seamless and helpful as possible, after all your product has just failed in some way and you wish (a) to mollify the user; and (b) to solicit their assistance in obtaining a full report.

You would think …

In the following I will reflect on what goes wrong in Adobe’s crash reporting and some  lessons we can learn from it.

(more…)

Just scanning a few Google Tech Talks on YouTube.  I don’t visit it often, but followed a link from Rob Style’s twitter.  I find the video’s a bit slow, so tend to flick through with the sound off, really wishing they had fast forward buttons like a DVD as quite hard to pull the little slider back and forth.

One talk was by Stuart Hameroff on A New Marriage of Brain and Computer.  He is the guy that works with Penrose on the possibility that quantum effects in microtubules may be the source of consciousness.  I notice that he used calculations for computational capacity based on traditional neuron-based models that are very similar to my own calculations some years ago in “the brain and the web” when I worked out that the memory and computational capacity of a single human brain is very similar to those of the entire web. Hameroff then went on to say that there are an order of magnitude more microtubules (sub-cellular structures, with many per neuron), so the traditional calculations do not hold!

Microtubules are fascinating things, they are like little mechano sets inside each cell.  It is these microtubules that during cell division stretch out straight the chromosomes, which are normally tangled up the nucleus.  Even stranger those fluid  movements of amoeba gradually pushing out pseudopodia, are actually made by mechanical structures composed of microtubules, only looking so organic because of the cell membrane – rather like a robot covered in latex.

The main reason for going to the text talks was one by Steve Souders “Life’s Too Short – Write Fast Code” that has lots of tips for on speeding up web pages including allowing Javascript files to download in parallel.  I was particularly impressed by the quantification of costs of delays on web pages down to 100ms!

This is great.  Partly because of my long interest in time and delays in HCI. Partly because I want my own web scripts to be faster and I’ve already downloaded the Yahoo! YSlow plugin for FireFox that helps diagnose causes of slow pages.  And partly  because I get so frustrated waiting for things to happen, both on the web and on the desktop … and why oh why does it take a good minute to get a WiFi connection ….  and why doesn’t YouTube introduce better controls for skimming videos.

… and finally, because I’d already spent too much time skimming the tech talks, I looked at one last talk: David Levy, “No Time To Think” … how we are all so rushed that we have no time to really think about problems, not to mention life¹.  At least that’s what I think it said, because I skimmed it rather fast.

1. see also my own discussion of Slow Time [back]

Looked at web stats for this blog for first time in ages.  IE is still top browser in raw hits, but between them Firefox and Mozilla  family have 39% above IE at 36%.  Is this just that there are more Mac users amongst HCI people and academics, or is Mozilla winning the browser wars?