Struggling with Heidegger

Heidegger and hammers have been part of HCI’s conceptualisation from pretty much as long as I can recall.  Although maybe I first heard the words at some sort of day workshop in the late 1980s as the hammer example as used in HCI annoyed me even then, so let’s start with hammers.


I should explain that problems with the hammer example are not my current struggles with Heidegger!  For the hammer it is just that Heidegger’s ‘ready at hand’ is often confused with ‘walk up and use’.  In  Heidegger ready-at-hand refers to the way one is focused on the nail, or wood to be joined, not the hammer itself:

“The work to be produced is the “towards which” of such things as the hammer, the plane, and the needle” (Being and Time1, p.70/99)

To be ‘ready to hand’ like this typically requires familiarity with the equipment (another big Heidegger word!), and is very different from the way a cash machine or tourist information systems should be in some ways accessible independent of prior knowledge (or at least only generic knowledge and skills).

My especial annoyance with the hammer example stems from the fact that my father was a carpenter and I reckon it took me around 10 years to learn how to use a hammer properly2!  Even holding it properly is not obvious, look at the picture.

There is a hand sized depression in the middle.  If you have read Norman’s POET you will think, “ah yes perceptual affordance’, and grasp it like this:

But no that is not the way to hold it!  If try to use it like this you end up using the strength of your arm to knock in the nail and not the weight of the hammer.

Give it to a child, surely the ultimate test of ‘walk up and use’, and they often grasp the head like this.

In fact this is quite sensible for a child as a ‘proper’ grip would put too much strain on their wrist.  Recall  Gibson’s definition of affordance was relational3, about the ecological fit between the object and the potential actions, and the actions depends on who is doing the acting.  For a small child with weaker arms the hammer probably only affords use at all with this grip.

In fact the ‘proper’ grip is to hold it quite near the end where you can use the maximum swing of the hammer to make most use of the weight of the hammer and its angular momentum:

Anyway, I think maybe Heidegger knew this even if many who quote him don’t!


OK, so its alright me complaining about other people mis-using Heidegger, but I am in the middle of writing one of the chapters for TouchIT and so need to make sure I don’t get it wrong myself … and there my struggles begin.  I need to write about ready-to-hand and present-to-hand.   I thought I understood them, but always it has been from secondary sources and as I sat with Being and Time in one hand, my Oxford Companion to Philosophy in another and various other books in my teeth … I began to doubt.

First of all what I thought the distinction was:

  • ready at hand — when you are using the tool and it is invisible to you, you just focus on the work to be done with it
  • present at hand — when there is some sort of breakdown, the hammer head is loose or you don’t have the right tool to hand and so start to focus on the tools themsleves rather than on the job at hand

Scanning the internet this is certainly what others think, for example blog posts at 251 philosophy and Matt Webb at Berg4.  Koschmann, Kuutti and Hickman produced an excellent comparison of breakdown in Heidegger, Leont’ev and Dewey5, and from this it looks as though the above distinction maybe comes Dreyfus summary of Heidegger — but again I don’t have a copy of Dreyfus’ “Being-in-the-World“, so not certain.

Now this is an important distinction, and one that Heidegger certainly makes.  The first part is very clearly what Heidegger means by ready-to-hand:

“The peculiarity of what is proximally to hand is that, in its readiness-to-hand, it must, as it were, withdraw … that with which we concern ourselves primarily is the work …” (B&T, p.69/99)

The second point Heidegger also makes at length distinguishing at least three kinds of breakdown situation.  It just seems a lot less clear whether ‘present-at-hand’ is really the right term for it.  Certainly the ‘present-at-hand’ quality of an artefact becomes foregrounded during breakdown:

“Pure presence at hand announces itself in such equipment, but only to withdraw to the readiness-in-hand with which one concerns oneself — that is to say, of the sort of thing we find when we put it back into repair.” (B&T, p.73/103)

But the preceeding sentance says

“it shows itself as an equipmental Thing which looks so and so, and which, in its readiness-to-hand as looking that way, has constantly been present-at-hand too.” (B&T, p.73/103)

That is present-at-hand is not so much in contrast to ready-at-hand, but in a sense ‘there all along’; the difference is that during breakdown the presence-at-hand becomes foregrounded. Indeed when ‘present-at-hand’ is first introduced Heidegger appears to be using it as a binary distinction between Dasein, (human) entities that exist and ponder their existence, and other entities such as a table, rock or tree (p. 42/67).  The contrast is not so much between ready-to-hand and present-to-hand, but between ready-to-hand and ‘just present-at-hand’ (p.71/101) or ‘Being-just-present-at-hand-and-no-more’ (p.73/103). For Heidegger to seems not so much that ‘ready-to-hand’ stands in in opposition to ‘present-to-hand’; it is just more significant.

To put this in context, traditional philosophy had focused exclusively on the more categorically defined aspects of things as they are in the world (‘existentia’/present-at-hand), whilst ignoring the primary way they are encountered by us (Dasein, real knowing existence) as ready-to-hand, invisible in their purposefulness.  Heidegger seeks to redress this.

“If we look at Things just ‘theoretically’, we can get along without understanding readiness-to-hand.” (B&T p.69/98)

Heidegger wants to avoid the speculation of previous science and philosophy. Although it is not a Heidegger word, I use ‘speculation’ here with all of its connotations, pondering at a distance, but without commitment, or like spectators at a sports stadium looking in at something distant and other.  In contrast, ready-to-hand suggests commitment, being actively ‘in the world’ and even when Heidegger talks about those moments when an entity ceases to be ready-to-hand and is seen as present-to-hand, he uses the term circumspection — a casting of the eye around, so that the Dasein, the person, is in the centre.

So present-at-hand is simply the mode of being of the entities that are not Dasein (aware of their own existence), but our primary mode of experience of them and thus in a sense the essence of their real existence is when they are ready-to-hand.  I note Roderick Munday’s useful “Glossary of Terms in Being and Time” highlights just this broader sense of present-at-hand.

Maybe the confusion arises because Heidegger’s concern is phenomenological and so when an artefact is ready-to-hand and its presence-to-hand ‘withdraws’, in a sense it is no longer present-to-hand as this is no longer a phenomenon; and yet he also seems to hold a foot in realism and so in another sense it is still present-to-hand.  In discussing this tension between realism and idealism in Heidegger, Stepanich6 distinguishes present-at-hand and ready-to-hand, from presence-to-hand and readiness-to-hand — however no-one else does this so maybe that is a little too subtle!

To end this section (almost) with Heidegger’s words, a key statement, often quoted, seems to say precisely what I have argued above, or maybe precisely the opposite:

“Yet only by reason of something present-at-hand ‘is there’ anything ready-to-hand.  Does it follow, however, granting this thesis for the nonce, that readiness-to-hand is ontologically founded upon presence-at-hand?” (B&T, p.71/101)

What sort of philosopher makes a key point through a rhetorical question?

So, for TouchIT, maybe my safest course is to follow the example of the Oxford Companion to Philosophy, which describes ready-to-hand, but circumspectly never mentions present-to-hand at all?

and anyway what’s wrong with …

On a last note there is another confusion, or maybe mistaken attitude, that seems to be common when referring to ready-to-hand.  Heidegger’s concern was in ontology, understanding the nature of being, and so he asserted the ontological primacy of the ready-to-hand, especially in light of the previous dominant concerns of philosophy.  However, in HCI, where we are interested not in the philosophical question, but the pragmatic one of utility, usability, and experience, Heidegger is often misapplied as a kind of fetishism of engagement, as if everything should be ready-to-hand all the time.

Of course for many purposes this is correct, as I type I do not want to be aware of the keys I press, not even of the pages of the book that I turn.

Yet there is also a merit in breaking this engagement, to encourage reflection and indeed the circumspection that Heidegger discusses.  Indeed Gaver et al.’s focus on ambiguity in design7 is often just to encourage that reflection and questioning, bringing things to the foreground that were once background.

Furthermore as HCI practitioners and academics we need to both take seriously the ready-to-hand-ness of effective design, but also (just as Heidegger is doing) actually look at the ready-to-hand-ness of things seeing them and their use not taking them for granted.  I constantly strive to find ways to become aware of the mundane, and offer students tools for estrangement to look at the world askance8.

“To lay bare what is  just present-at-hand and no more, cognition must first penetrate beyond what is ready-to-hand in our concern.” (B&T, p.71/101)

This ability to step out and be aware of what we are doing is precisely the quality that Schon recognises as being critical for the ‘Reflective Practioner‘.  Indeed, my practical advice on using the hammer in the footnotes below comes precisely through reflection on hammering, and breakdowns in hammering, not through the times when the hammer was ready-to-hand..

Heidegger is indeed right that our primary existence is being in the world, not abstractly viewing it from afar.  And yet, sometimes also, just as Heidegger himself did as he pondered and wrote about these issues, one of our crowning glories as human beings is precisely that we are able also in a sense to step outside ourselves and look in wonder.

  1. In common with much of the literature the page references to Being and Time are all of the form p.70/99 where the first number refers to the page numbers in the original German (which I have not read!) and the second number to the page in Macquarrie and Robinson’s translation of Being and Time published by Blackwell.[back]
  2. Practical hammering – a few tips: The key thing is to focus on making sure the face of the hammer is perpendicular to the nail, if there is a slight angle the nail will bend.  For thin oval wire nails, if one does bend do not knock the nail back upright, most likely it will simply bend again and just snap.  Instead, simply hit the head of the nail while still bent, but keeping the hammer face perpendicular to the nail not the hole.  So long as the nail has cut any depth of hole it will simply follow its own path and straighten of its own accord.[back]
  3. James Gibson. The Ecological Approach to Visual Perception[back]
  4. Matt Webb’s post appears to be quoting Paul Dourish’ “Where the Action Is”, but I must have lent my copy to someone, so not sure of this is really what Paul thinks.[back]
  5. Koschmann, T., Kuutti, K. & Hickman, L. (1998). The Concept of Breakdown in Heidegger, Leont’ev, and Dewey and Its Implications for Education. Mind, Culture, and Activity, 5(1), 25-41. doi:10.1207/s15327884mca0501_3[back]
  6. Lambert Stepanich. “Heidegger: Between Idealism and Realism“, The Harvard Review of Philosophy, Vol 1. Spring 1991.[back]
  7. Bill Gaver, Jacob Beaver, and Steve Benford, 2003. Ambiguity as a resource for design. CHI ’03.[back]
  8. see previous posts on “mirrors and estrangement” and “the ordinary and the normal“[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! (rather then, 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=[back]
  3. Hall, W., Davis, H., and Hutchings, G. 1996 Rethinking Hypermedia: the Microcosm Approach. Kluwer Academic Publishers.[back]

data types and interpretation in RDF

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=""/>

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>


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]

Descartes: Principles of Philosophy

I have just read Descartes‘ “Principles of Philosophy” – famous for “Cogito ergo sum“.  I have read commentaries on Descartes before, but never the original (or at least a translation1, I don’t read Latin!).  Now-a-days “Cartesian thinking” is often used in a derogatory way, symbolising a narrow, reductionist and simplistic world-view.  However, reading “Principles” in full reveals a man with a rich and deep insight of which his rational and analytic philosophy forms a part.

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  1. René Descartes, 1644, Principles of Philosophy, trans. George MacDonald Ross, 1998–1999[back]

Last days in Rome

Five weeks in Rome seemed like a long time, but with a week mainly in Milan and Trento and the coming week in India, in fact just three full weeks and they have flown by.

I had imagined long evenings reading philosophy of the physical world, and weekend afternoons under the shade of a tree on the Palatine Hill, but it didn’t quite work out like that.

Of the ‘work’ books I brought to Rome (and borrowed here), I have only read Gibson’s “The Ecological Approach to Visual Perception“, Goodman’s “Languages of Art” and Noe’s “Action in Perception“; and of the ‘fun’ books only Tamara Pierce’s  The Healing in the Vine. I have flights back and forth to India next week, so may manage a bit more then, but mainly overnight, so I fear most of my bookshelf will return to the UK unread 🙁

One of the reasons is evident on a table in my office. Normally at home when I finish something the paper from it ‘goes away’ somewhere, but here as I have read something or finished with printouts I have been laying them out on an empty table in case I wanted to refer to them again. So the table is now covered, smothered, in the results of three weeks normal academic work. I am amazed, if not aghast, at the volume. The entire table between 50 and 500 sheets thick in paper, I’d guess somewhere between one and two thousand sheets of paper printed, read and to be discarded. I mentioned climate change in last post and, boy, it looks like one academic can wipe out most of the Amazon and drown the South Pacific single-handed.

I have printed out a bit more than I normally would as I knew I couldn’t print things during the evenings at the apartment and so tended to do so ‘just in case’ before heading out of the office.  So normally some of this would have been dealt with purely electronically, but nevertheless, the volume is frightening. And I don’t think this was a particularly unusual three weeks in terms of volume.

So what is here?

On the one side there is input: there is a PhD thesis, twenty of or so papers reviewed or meta-reviewed during the period, several papers given to me by people to read while here, one EPSRC grant proposal I reviewed, and a few piles of papers I was referring to in things I was producing during the period. On the output side during the three weeks two grant proposals have been submitted, one other needed extra work and a STREP is in process of preparation for the autumn, two journal papers, a book chapter, an article for Interfaces, some work on other papers, and a few internal reports for discussions about future work. Other things never saw paper: a couple of long blog posts (5000 words between them), three job references, innumerable emails, and the preparation for 33 hours of masters and PhD teaching and two other talks.

Although I often feel busy seeing all that paper makes it tangible and does shock me somewhat. But I know this is relatively normal; Aaron Quigley‘s twitter feed is exhausting just to read!

So, did I see much of Rome …

Well on one Sunday, with Manuela, Francesco and his daughter I visited the annual open-air art exhibition of the 100 painters in Via Margutta (between Piazza di Spagna and Piazza del Popolo). One of the artists was, Paul Van den Nieuwenhof, a friend of Manuela and Francesco from whom they had recently bought a still life (apples). Paul’s real passion is more avant-garde installations, but the still lives are mainly focused on the Italian market where modern art is not so popular. Looking at his more traditional paintings I was impressed again by the way an expert oil painter creates light from pigment: shapes and solids seem more the medium and the pure light the message.

Another Sunday I took lunch in a pizzeria on the Trastevere (my favourite place for both pizza and bread), and took a meandering path there nearly as far as St Angelo and sauntering along the Tiber … but mainly because I took the wrong road out of Largo di Torre Argentina. In the middle of Argentina is a large exposed ruin, and I was told (but by whom I have forgotten!) that this was where Julius Caesar was assassinated.

Incidentally, while in Milan (which I will write about separately sometime) I learnt that in Julius Caesar’s time it would have been pronounced Kaiser as in German today, the softer ‘c’ came later.

Apart from that I am ashamed to say no art galleries or exhibitions, and my main view of Rome has been the area between Termini station, the Department, and my appartment, ‘Al Colosseo’, a lovely location within sight (just) of the Collosseum (see below).

However, most mornings I have taken a run down past the Colloseum as far as Circo Massimo and one or more laps of that. It is a popular spot for morning runners, although I prefer it best when I get there a little earlier. Not to avoid the others, but because from about 7am when the sun starts to rise it gets so hot. The most interesting end of Circo Massimo is currently boarded off as they do works there and in the last 2 weeks the far end has turned into a mini-stadium for Beach Soccer, I assume to coincide with the UEFA football next week.

Tonight it will be another pizza evening and I am promised it will be at a place that specialises in Roman-style pizzas and those lovely deep fried vegetables. Italy is about sun and ruins, about design and expensive cars and the Vatican and bureaucracy, … but above all it is about food and friends.

Language and Action (2): from observation to communication

Years ago I wrote a short CHI paper with Roberta Mancini and Stefano Levialdi “communication, action and history” all about the differences between language and action, but for the second time in a few weeks I am writing about the links. But of course there are both similarities and differences.

In my recent post about “language and action: sequential associative parsing“, I compared the role of semantics in the parsing of language with the similar role semantics plays in linking disparate events in our interpretation of the world and most significantly the actions of others. The two differ however in that language is deliberative, intentionally communicative, and hence has a structure, a rule-iness resulting from conventions; it is chosen to make it easier for the recipient to interpret. In contrast, the events of the world have structure inherent in their physical nature, but do not structure themselves in order that we may interpret them, their rule-iness is inherent not intentional. However, the actions of other people and animals often fall between the two.

In this post I will focus in on individual actions of creatures in the world and the way that observing others tells us about their current activities and even their intended actions, and thus how these observations becomes a resource for planning our own actions. However, our own actions are also the subject of observation and hence available to others. We may deliberately hide or obfuscate our intentions and actions if we do not wish others to ‘read’ what we are doing; however, we may also exaggerate them, making them more obvious when we are collaborating. That is, we shape our actions in the light of their potential observation by others so that they become an explicit communication to them.

This exaggeration is evident in computer environments and the physical world, and may even be the roots of iconic gesture and hence language itself.

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bookshelf in Rome

I posted a few weeks ago about books I had got to bring to Rome.  Since then I got another small collection because I had done some reviewing for Routledge.

Mostly philosophy of the mind and materiality … the latter to help as we work on the DEPtH book on Physicality, TouchIT

  • Shaun Gallagher, Dan Zahavi. The Phenomenological Mind: An Introduction to Philosophy of Mind and Cognitive Science, Routledge, 2007.
  • John Lechte. Fifty Key Contemporary Thinkers: From Structuralism to Post-Humanism, 2nd Edition, Routledge, 2007.
  • Jean-Paul Sartre.  Being and Nothingnes: An Essay on Phenomenological Ontology, 1943.  Routledge Classics, , 2nd Edition, 2003.
  • Jay Friedenberg. Artificial Psychology, Routledge , 2008.
  • Max Velmans.  Understanding Consciousness, Routledge, 2009.
  • Peter Carruthers. The Nature of the Mind, Routledge, 2003.

In fact, with these and the previous  set I had far too many even for a month of evenings, and below you can see the books I actually brought.

As well as a selection from the academic books also some fiction/leisure reading, some old favourites and some new ones:

  • How Green was My Valley, Richard Llewellyn – a Welshman has to read this :-/
  • The Catcher in the Rye, J.D. Salinger – a classic I’ve never read
  • More of the Good Life – the TV series was formative for me as a child, but 40 seemed so far away
  • Lark Rise to Candleford, Flora Thompson – some years since I’ve read it last, and have been loving the TV series, but I don’t think it has stayed very close to the book!
  • Nella Last’s War – this is the book that was the basis for the TV drama Housewife 49 and part of the Mass Observation that collected diaries from ordinary people across Britain during the Second World War.
  • Ruth, Elizabeth Gaskill – another classic that I’ve not read yet!
  • As I Walked Out One Midsummer Morning.  Laurie Lee’s account of travelling in Spain in the run up to the Civel War.  I read it in school for O’level.
  • Swallowdale, Arthur Ransome – Couldn’t find Swallow’s an Amazons, I think one of the girls might have it on their shelves!
  • The Shining Company, Rosemary Sutcliff – we have loads of her histroical novels for children.  I find that good children’s writing is so much better than most adult books, which often feel they need to be incomprehensible to be good.
  • The Growing Summer, Noel Streatfield – lovely story, children visiting a quirky old lady in west coast of Ireland.
  • Hovel in the Hills, Elizabeth West  – another book I’ve read many times, but not for many years.  True story about a couple who buy an old house on a Welsh hillside.

In addition, but missing from the picture, is one I borrowed from my daughter, Tamara Pierce’s  The Healing in the Vine, and one I’ve borrowed from Tiziana Catarci during my visit the Languages of Art.

So, two weeks in and how far have I got …

Well, been a little busy, two journal papers, a book chapter, an interfaces article, two 3 hour lectures to the masters students here, a seminar, reading thesis chapters and helping with two grant proposals … so not got very far through the bookshelf.

In fact, to be brutally honest, so far only finished the Tamora Pierce and nearly finished Gibson (just conclusions to go):

As you can see LOTS of notes on Gibson, I will write a very long blog sometime about this, but several others in line first!

But next week several train journeys, so may get through a few more books 🙂

the ordinary and the normal

I am reading Michel de Certeau’s “The Practice of Everyday Life“.  The first chapter begins:

The Practice of Everyday Life (cover image)The erosion and denigration of the singular or the extraordinary was announced by The Man Without Qualities1: “…a heroism but enormous and collective, in the model of ants” And indeed the advent of the anthill society began with the masses, … The tide rose. Next it reached the managers … and finally it invaded the liberal professions that thought themselves protected against it, including even men of letters and artists.”

Now I have always hated the word ‘normal’, although loved the ‘ordinary’.  This sounds contradictory as they mean almost the same, but the words carry such different connotations. If you are not normal you are ‘subnormal’ or ‘abnormal’, either lacking in something or perverted.  To be normal is to be normalised, to be part of the crowd, to obey the norms, but to be distinctive or different is wrong.  Normal is fundamentally fascist.

In contrast the ordinary does not carry the same value judgement.  To be different from ordinary is to be extra-ordinary2, not sub-ordinary or ab-ordinary.  Ordinariness does not condemn otherness.

Certeau is studying the everyday.  The quote is ultimately about the apparently relentless rise of the normal over the ordinary, whereas Certeau revels in  the small ways ordinary people subvert norms and create places within the interstices of the normal.

The more I study the ordinary, the mundane, the quotidian, the more I discover how extraordinary is the everyday3. Both the ethnographer and the comedian are expert at making strange, taking up the things that are taken for granted and holding them for us to see, as if for the first time. Walk down an anodyne (normalised) shopping street, and then look up from the facsimile store fronts and suddenly cloned city centres become architecturally unique.  Then look through the crowd and amongst the myriad incidents and lives around, see one at a time, each different.

Sometimes it seems as if the world conspires to remove this individuality. The InfoLab21 building that houses the Computing Dept. at Lancaster was sort listed for a people-centric design award of ‘best corporate workspace‘.  Before the judging we had to remove any notices from doors or any other sign that the building was occupied, nothing individual, nothing ordinary, sanitised, normalised.

However, all is not lost.  I was really pleased the other day to see a paper  “Making Place for Clutter and Other Ideas of Home4. Laural, Alex and Richard are looking at the way people manage the clutter in their homes: keys in bowls to keep them safe, or bowls on a worktop ready to be used.  They are looking at the real lives of ordinary people, not the normalised homes of design magazines, where no half-drunk coffee cup graces the coffee table, nor the high-tech smart homes where misplaced papers will confuse the sensors.

Like Fariza’s work on designing for one person5, “Making a Place for Clutter” is focused on single case studies not broad surveys.  It is not that the data one gets from broader surveys and statistics is not important (I am a mathematician and a statistician!), but read without care the numbers can obscure the individual and devalue the unique.  I heard once that Stalin said, “a million dead in Siberia is a statistic, but one old woman killed crossing the road is a national disaster”. The problem is that he could not see that each of the million was one person too. “Aren’t two sparrows sold for only a penny? But your Father knows when any one of them falls to the ground.”6.

We are ordinary and we are special.

  1. The Man without Qualities, Robert Musil, 1930-42, originally: Der Mann ohne Eigenschafte. Picador Edition 1997, Trans.  Sophie Wilkins and  Burton Pike: Amazon | Wikipedia[back]
  2. Sometimes ‘extraordinary’ may be ‘better than’, but more often simply ‘different from’, literally the Latin ‘extra’ = ‘outside of’[back]
  3. as in my post about the dinosaur joke![back]
  4. Swan, L., Taylor, A. S., and Harper, R. 2008. Making place for clutter and other ideas of home. ACM Trans. Comput.-Hum. Interact. 15, 2 (Jul. 2008), 1-24. DOI=[back]
  5. Described in Fariza’s thesis: Single Person Study: Methodological Issues and in the notes of my SIGCHI Ireland Inaugural Lecture Human-Computer Interaction in the early 21st century: a stable discipline, a nascent science, and the growth of the long tail.[back]
  6. Matthew 10:29[back]

Searle’s wall, computation and representation

Reading a bit more of Brain Cantwell Smith’s “On the Origin of Objects”  and he refers (p.30-31) to Searle‘s wall that, according to Searle, can be interpreted as implementing a word processor.  This all hinges on predicates introduced by Goodman such as ‘grue’, meaning “green is examined before time t or blue if examined after”:

grue(x) = if ( now() < t ) green(x)
          else blue(x)

The problem is that an emerald apparently changes state from grue to not grue at time t, without any work being done.  Searle’s wall is just an extrapolation of this so that you can interpret the state of the wall at a time to be something arbitrarily complex, but without it ever changing at all.

This issue of the fundamental nature of computation has long seemed to me the ‘black hole’ at the heart of our discipline (I’ve alluded to this before in “What is Computing?“).  Arguably we don’t understand information much either, but at least we can measure it – we have a unit, the bit; but with computation we cannot even measure except without reference to specific implementation architecture whether Turing machine or Intel Core.  Common sense (or at least programmer’s common sense) tells us that any given computational device has only so much computational ‘power’ and that any problem has a minimum amount of computational effort needed to solve it, but we find it hard to quantify precisely.  However,  by Searle’s argument we can do arbitrary amounts of computation with a brick wall.

For me, a defining moment came about 10 years ago, I recall I was in Loughbrough for an examiner’s meeting and clearly looking through MSc scripts had lost it’s thrill as I was daydreaming about computation (as one does).  I was thinking about the relationship between computation and representation and in particular the fast (I think fastest) way to do multiplication of very large numbers, the Schönhage–Strassen algorithm.

If you’ve not come across this, the algorithm hinges on the fact that multiplication is a form of convolution (sum of a[i] * b[n-i]) and a Fourier transform converts convolution into pointwise multiplication  (simply a[i] * b[i]). The algorithm looks something like:

1. represent numbers, a and b, in base B (for suitable B)
2. perform FFT in a and b to give af and bf
3. perform pointwise multiplication on af and bf to give cf
4. perform inverse FFT on cf to give cfi
5. tidy up cfi a but doing carries etc. to give c
6. c is the answer (a*b) in base B

In this the heart of the computation is the pointwise multiplication at step 3, this is what ‘makes it’ multiplication.  However, this is a particularly extreme case where the change of representation (steps 2 and 4) makes the computation easier. What had been a quadratic O(N2) convolution is now a linear O(N) number of pointwise multiplications (strictly O(n) where n = N/log(B) ). This change of representation is in fact so extreme, that now the ‘real work’ of the algorithm in step 3 takes significantly less time (O(n) multiplications) compared to the change in representation at steps 2 and 4 (FFT is O( n log(n) ) multiplications).

Forgetting the mathematics this means the majority of the computational time in doing this multiplication is taken up by the change of representation.

In fact, if the data had been presented for multiplication already in FFT form and result expected in FFT representation, then the computational ‘cost’ of multiplication would have been linear … or to be even more extreme if instead of ‘representing’ two numbers as a and b we instead ‘represent’ them as a*b and a/b, then multiplication is free.  In general, computation lies as much in the complexity of putting something into a representation as it is in the manipulation of it once it is represented.  Computation is change of representation.

In a letter to CACM in 1966 Knuth said1:

When a scientist conducts an experiment in which he is measuring the value of some quantity, we have four things present, each of which is often called “information”: (a) The true value of the quantity being measured; (b) the approximation to this true value that is actually obtained by the measuring device; (c) the representation of the value (b) in some formal language; and (d) the concepts learned by the scientist from his study of the measurements. It would seem that the word “data” would be most appropriately applied to (c), and the word “information” when used in a technical sense should be further qualified by stating what kind of information is meant.

In these terms problems are about information, whereas algorithms are operating on data … but the ‘cost’ of computation has to also include the cost of turning information into data and back again.

Back to Searle’s wall and the Goodman’s emerald.  The emerald ‘changes’ state from grue to not grue with no cost or work, but in order to ask the question “is this emerald grue?” the answer will involve computation (if (now()<t) …).  Similarly if we have rules like this, but so complicated that Searle’s wall ‘implements’ a word processor, that is fine, but in order to work out what is on the word processor ‘screen’ based on the observation of the (unchanging) wall, the computation involved in making that observation would be equivalent to running the word processor.

At a theoretical computation level this reminds us that when we look at the computation in a Turing machine, vs. an Intel processor or lambda calculus, we need to consider the costs of change of representations between them.  And at a practical level, we all know that 90% of the complexity of any program is in the I/O.

  1. Donald Knuth, “Algorithm and Program; Information and Data”, Letters to the editor. Commun. ACM 9, 9, Sep. 1966, 653-654. DOI= [back]

matterealities and the physical embodiment of code

Last Tuesday morning I had the pleasure of entertaining a group of attendees to the Matterealities workshop @ lancaster. Hans and I had organised a series of demos in the dept. during the morning (physiological gaming, Firefly (intelligent fairylights), VoodooIO, something to do with keyboards) … but as computer scientists are nocturnal the demos did not start until 10am, and so I got to talk with them for around an hour beforehand :-/

The people there included someone who studied people coding about DNA, someone interested in text, anthropologosts, artists and an ex-AI man. We talked about embodied computation1, the human body as part of computation, the physical nature of code, the role of the social and physical environment in computation … and briefly over lunch I even strayed onto the modeling of regret … but actually a little off topic.

Alan driving

physicality – Played a little with sticks and stones while talking about properties of physical objects: locality of effect, simplicity of state, proportionality and continuity of effect2.

physical interaction – Also talked about the DEPtH project and previous work with Masitah on natural interaction. Based on the piccie I may have acted out driving when talking about natural inverse actions

ubiquity of computation – I asked the question I often do “How many computers do you have in your house” … one person admitted to over 10 … and she meant real computers3. However, as soon as you count the computer in the TV and HiFi, the washing machine and microwave, central heating and sewing machine the count gets bigger and bigger. Then there is the number you carry with you: mobile phone, camera, USB memory stick, car keys (security codes), chips on credit cards.

FireFly on a Christmas treeHowever at the Firefly demo later in the morning they got to see what may be the greatest concentration of computers in the UK … and all on a Christmas Tree. Behind each tiny light (over 1000 of them) is a tiny computer, each as powerful as the first PC I owned allowing them to act together as a single three dimensional display.

embodiment of computation – Real computation always happens in the physical world: electrons zipping across circuit boards and transistors routing signals in silicon. For computation to happen the code (the instruction of what needs to happen) and the data (what it needs to happen with and to) need to be physically together.

The Turing Machine, Alan Turing’s thought experiment, is a lovely example of this. Traditionally the tape in the Turing machine is thought of as being dragged across a read-write head on the little machine itself.

However … if you were really to build one … the tape would get harder and harder to move as you used longer and longer tapes. In fact it makes much more sense to think of the little machine as moving over the tape … the Turing machine is really a touring machine (ouch!). Whichever way it goes, the machine that knows what to do and the tape that it must do it to are brought physically together4.

This is also of crucial importance in real computers and one of the major limits on fast computers is the length of the copper tracks on circuit boards – the data must come to the processor, and the longer the track the longer it takes … 10 cm of PCB is a long distance for an electron in a hurry.
Alanbrain as a computer – We talked about the way each age reinvents humanity in terms of its own technology: Pygmalion in stone, clockwork figures, pneumatic theories of the nervous system, steam robots, electricity in Shelley’s Frankenstein and now seeing all life through the lens of computation.

This withstanding … I did sort of mention the weird fact (or is it a factoid) that the human brain has similar memory capacity to the web5 … this is always a good point to start discussion 😉

While on the topic I did just sort of mention the socio-organisational Church-Turing hyphothesis … but that is another story

more … I recall counting the number of pairs of people and the number of seat orderings to see quadratic (n squared) and exponential effects, the importance of interpretation, why computers are more than and less than numbers, the Java Virtual Machine, and more, more, more, … it was very full hour

AlanLcoblo - artefactsAlan

  1. I just found notes I’d made for web page in embodied computation 5 years ago … so have put the notes online[back]
  2. see preface to Physicality 2006 proceedings[back]
  3. I just found an online survey on How many computers in your house[back]
  4. Yep I know that Universal Turing machine has the code on the tape, but there the ‘instructions’ to be executed are basically temporarily encoded into the UTM’s state while it zips off to the data part of the tape.[back]
  5. A. Dix (2005). the brain and the web – a quick backup in case of accidents. Interfaces, 65, pp. 6-7. Winter 2005.[back]