Tag Archives: human computer interaction

matterealities and the physical embodiment of code

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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.
    http://www.hcibook.com/alan/papers/brain-and-web-2005/[back]

Practicing security

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Last week I was stuck a night in Frankfurt due to the high winds. Soon after I settled into the 17th floor of the Holiday Inn, gusts screaming round the building, I got a call on my mobile. I thought it would be my taxi driver confirming the time for the re-booked flight the next day, but instead there was an unfamiliar voice:

“This is HM Revenue and Customs, we have a message for you, but first can we confirm your name and address”

Actually name and address to phone number is not that secret, but still I asked:

“How do I know you are who you say you are?”

“If you prefer you can ring back on …. it is to your advantage”

I checked that it would be OK to ring the next day on my return and rang off … I didn’t say (life is too short), that being given a number to ring back does not increase my confidence unless I can verify it.

In fact the next day I checked on the HMR&C site and the number was their helpline. However, this call had many hall marks of a fraudulent call: how could I, or a less technically aware citizen know this was a good call? In this case the information requested was relatively innocuous (but of course could easily continue, “and date of birth … bank details …”) and the phone number given was an 0845 number which costs the recipient money … either genuine or high-value fraud. Of course, if I was fradulently ringing up people pretending to be HMR&C, at any sign of trouble giving the genuine helpline numer would be just what I would do to allay suspicion!

It is not just HMRC that give calls like this; banks and credit card companies are forever ringing up and asking you to confirm your identity … and that usually does include giving some form of security code. But they have rung you up, so have more confidence in who you are then you do in them, yet never offer any means to confirm their identitiy.

Email too: I have received various mails from banks which look very like phishing emails. In one case I received an email where the domain of the sender was different from the domain of the reply email and different again from the domain of the URL link. It goes to say that none of these were the same as the standard domain of the bank. In this case the only reason I knew it was not phishing was that it offered information and did not request anything secure.

By sending emails and making phone calls that are virtually indistinguishable from fraudulent ones, the banks (and even HMR&C) are training us to be victims of fraud.

Literally we are encouraged to practice being insecure.