Posts Tagged ‘reading’
30
Aug

The Landing Pilot is the Non-Handling Pilot until the “decision altitude” call, when the Handling Non-Landing Pilot hands the handling to the Non-Handling Landing Pilot, unless the latter calls “go-around”, in which case the Handling Non-Landing Pilot, continues Handling and the Non-Handling Landing Pilot continues non-handling until the next call of “land” or “go-around”, as appropriate.

In view of the recent confusion over these rules, it was deemed necessary to restate them clearly.

– British Airways memorandum, quoted in Pilot Magazine, December 1996 (and in The Pragmatic Programmer, which is where I read it).

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27
Apr

Programming Collective IntelligenceI’ve been reading a fantastic book written by Toby Segaran called Programming Collective Intelligence: Building Smart Web 2.0 Applications. I’m about two thirds of the way through, but it’s so good that I’m not going to wait until I finish reading it before blogging it. Essentially, it’s a recipe book for machine learning algorithms that you’re likely to find under the hood of many successful modern web sites: clustering, support vector machines, decision trees, simulated annealing, Bayesian classification and so on. The AI course at uni was a bit light on in terms of statistical machine learning techniques, but this book makes up for it. All the code in the book is written in Python and can be downloaded from the author’s website. The algorithms in the book may prove to be highly useful for my work in ubiquitous computing, too.

Coincidentally, according to the most recent entry in his blog, Toby will be giving a talk on a topic sort of related to one I’ve been thinking about as a possible project at NICTA: Creating Semantic mashups: Bridging Web 2.0 and the Semantic Web.

It turns out that Toby is also a fan of GTD, and he’s written his own web based GTD tool. It doesn’t look much, but it’s gained some favourable reviews.

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13
Mar

Karen came across a fantastic online book store called The Book Depository. Its prices are highly competitive. But the best part is that they offer free shipping worldwide. We’ve already ordered five books from them: That’s Not My Puppy; That’s Not My Lion; Dear Zoo; The Art of the Start; and Programming Collective Intelligence. They arrived separately, but all within a week, in well padded packaging. One word of caution: be sure to visit the right web site. It’s http://www.bookdepository.co.uk/, NOT http://www.thebookdepository.co.uk/.

11
Feb

If Apple went bust, people would have withdrawal symptoms. If a rival company went, people would buy another computer.

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28
Jan

I’ve been reading over old ubicomp papers in preparation for a new project at NICTA. So it was that I found myself reading “Charting Past, Present, and Future Research in Ubiquitous Computing“, by Gregory Abowd and Elizabeth Mynatt (whom, incidentally, should surely be listed among those ubiquitous computing researchers who inspire me – particularly Abowd, whose work I’ve followed since my Honours year in 2000, and whose books were often referenced in the HCI course I took a couple of years before that). One of the most important passages in that paper, to my mind, was tucked away in section 6.1.1, Finding a Human Need (the emphasis is mine):

It is important in doing ubicomp research that a researcher build a compelling story, from the end-user’s perspective, on how any system or infrastructure to be built will be used. The technology must serve a real or perceived human need, because, as Weiser [1993] noted, the whole purpose of ubicomp is to provide applications that serve the humans. The purpose of the compelling story is not simply to provide a demonstration vehicle for research results. It is to provide the basis for evaluating the impact of a system on the everyday life of its intended population. The best situation is to build the compelling story around activities that you are exposed to on a continuous basis. In this way, you can create a living laboratory for your work that continually motivates you to “support the story” and provides constant feedback that leads to better understanding of the use.

Designers of a system are not perfect, and mistakes will be made. Since it is already a difficult challenge to build robust ubicomp systems, you should not pay the price of building a sophisticated infrastructure only to find that it falls far short of addressing the goals set forth in the compelling story. You must do some sort of feasibility study of cutting-edge applications before sinking substantial effort into engineering a robust system that can be scrutinized with deeper evaluation. However, these feasibility evaluations must still be driven from an informed, user-centric perspective—the goal is to determine how a system is being used, what kinds of activities users are engaging in with the system, and whether the overall reactions are positive or negative. Answers to these questions will both inform future design as well as future evaluation plans. It is important to understand how a new system is used by its intended population before performing more quantitative studies on its impact.

It strikes me that too few ubicomp research groups heed this, seemingly obvious, advice, including our own. Though we might occasionally attempt to build a story, it is not often compelling, and I’ve read far too many papers that suffer from the same problem (caveat: I specifically exclude Karen’s work from this blunt introspective analysis because her work is typically very well motivated, and compelling; and she read the paper I’ve just quoted early on in her Ph.D. and took note of it). I don’t think it’s a coincidence that the most successful ubiquitous computing researchers have taken this advice to heart. I want to make sure that the new project at NICTA does do these things properly.

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17
Jan

Ben delicioused me a link to an interesting paper called “Bowl: token-based media for children“. It describes a media player that is controlled by placing various objects (tokens) into a bowl. The idea was to create a control interface that is easy for children to use and which establishes links between particular physical objects and digital media. Aside from being a really cool means for interacting with a media player, it would have to be one of the neatest uses of RFID that I’ve come across so far. The bowl (or rather the platform that the bowl sits on) is augmented with an RFID reader. The various objects are augmented with RFID tags. When an object is placed in the bowl, an associated piece of media plays on the screen. For example, when a Mickey Mouse doll is put into the bowl, a Mickey Mouse cartoon plays. In theory, various combinations of objects might also have meaning. The system might be configured so that if Mickey Mouse and Donald Duck are placed in the bowl, a cartoon featuring both these characters starts playing. The system becomes very social and conversational when homemade objects are augmented with RFID and linked to, say, home video clips or family photos, as demonstrated by the experiment reported in the paper.

I wonder what sorts of casual, natural interactions such as those induced by Bowl might make sense in the domain I’m working in? What are the relevant artefacts that could be augmented to create new meanings for the people who interact with them?

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15
Jan

Last week I read a 2004 paper called MapReduce: Simplified Data Processing on Large Clusters. It was written by a couple of Google researchers, and details a simple programming model and library for processing large datasets in parallel. MapReduce is used by Google under the hood for lots of different things, from indexing to machine learning to graph computation. Very handy indeed.

So imagine my surprise to find in last Friday’s edition of ACM TechNews that this paper has been republished in Communications of the ACM this month, albeit in a slightly shorter form. Aside from a few cosmetic changes (updated figure and table), the content of the papers is the same. That is, you don’t gain any knowledge from reading one of the papers that you wouldn’t gain from reading the other. There is no indication in the more recent publication that so much content has been duplicated from an earlier paper, though there is a citation to the older paper. In short, this is not new material, having been first published more than three years ago. Communications of the ACM seems to be trialling a new model, whereby the best articles from conferences are modified and republished for the ACM audience. But seriously, the modifications in the republished MapReduce article are negligible. What gives?

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17
Dec

Albert Einstein once said In the middle of every difficulty lies opportunity. I suppose it is this observation that lies at the heart of The Upside of Down: Catastrophe, Creativity, and the Renewal of Civilization, a book by Thomas Homer-Dixon. I was really looking forward to reading this book, having read an interview that New Scientist did with its author a while ago. So interested was I to read it, that I sent the author an e-mail asking him if it would be published in Australia, and if so, when. To my surprise, not only did I get an immediate reply from Homer-Dixon telling me that he was in negotiations with an Australian publishing company, he was kind enough to send me another e-mail months later when the book was finally launched in this country. I bought myself a copy immediately.

The Upside of Down identifies five “tectonic” stresses that our world is facing. These stresses relate to population, energy, environment, climate and economics, and they can combine with multipliers – the major ones being the rising connectivity of our world and the increasingly disproportionate power of small groups of people who may wish to do horrible things – to cause synchronous failure, or the kind of catastrophic collapse of our civilisation from which it would be hard or impossible to recover.

Homer-Dixon also espouses an interesting theory about the role played by energy return on investment (EROI) in the sustainability of a civilisation, and illustrates this theory using the Roman Empire as an example. In brief, civilisations become harder to sustain as the ratio between the energy expended to generate energy and the generated energy itself grows smaller. The Romans were dependent on food-based energy sources: man- and animal-power drove the Roman economy, and these fuelled by grain and so forth. The Romans exhausted large swathes of agricultural land, and as it did so, its EROI became smaller and smaller. Our civilisation is, of course, locked into an oil-based economy, and it’s not clear how far away we are from serious oil shortages.

The book also discusses panarchy as it relates to systems theory. Panarchy essentially describes the adaptive cycles of growth, accumulation, restructuring, and renewal of any complex system. There comes a time in the system when restructuring or collapse is inevitable. In naturally occuring systems the collapse is followed by a period of adaptation and creativity in which the system slowly regains its complexity. Homer-Dixon feels that in human systems, however, the growth phase may be artificially prolonged, resulting in a much more devastating collapse.

Overall, the book is a thoroughly interesting read. Unfortunately, though, its penultimate and concluding chapters let it down badly. The reasons for this are numerous. For starters, Homer-Dixon fails to offer any serious solutions. We don’t know what the breakdown of our societies will look like, he says, but we can still figure out how we might respond. And how might we do this?

In vigorous, wide-ranging, yet disciplined conversation among ourselves, we can develop scenarios of what kinds of breakdown could occur. In this conversation, we shouldn’t be afraid to think “outside the box” – try to imagine the unimaginable – because in a non-linear world under great pressure, we’re certain to make wrong predictions if we just extrapolate from current trends.

Although I don’t disagree with this per se, it is hardly the kind of visionary advice I was expecting from this policy wonk, whom, apparently, politicians around the world take quite seriously.

But it wasn’t just the lack of any real conclusions that left me cold. It was also the existence of several contradictions and a misunderstanding of some of the key scientific and economic theories underpinning the book.

First, Homer-Dixon seems to give more weight to the likelihood of targeted attacks as opposed to random failures, and therefore argues we ought to avoid scale-free networks as far as possible. Scale-free networks are prevalent thoughout nature and our societies, and they exhibit the property that their link distribution adheres to a power-law (i.e., a few nodes are highly connected whilst most others have only a small number of connections). This means that when a random node or link fails, the probability of major disruptions to the overall network is small. But if a few hubs (highly connected nodes) fail or are deliberately targeted, the effects can be disastrous. Yet there is little evidence to suggest targeted attacks are more likely than random failures, and he provides no indication that this is the case.

Second, the concluding chapters level serious criticisms at capitalism and markets, pointing the finger at the growth imperative and the widening gap between the richest and poorest people. While the latter is clearly true, it is also clear that capitalism is responsible for rescuing more people from poverty than any other system or sustained effort to date. As for the growth imperative, Homer-Dixon seems automatically to assume that growth comes only as a result of plundering the Earth’s resources, when in fact modern economic theory suggests growth actually comes from increases in efficiency and productivity. He also ascribes to capitalism the failures and poor choices of governments. Because western economies are well managed in the short term, they provide less opportunity for small collapses and the innovation that follows these collapses, which he acknowledges. But what would happen if governments had less to do with economic management? This is not a problem with free markets and capitalism but of its manifestation in the presence of governments who must optimise their policies to the short term in order to be re-elected.

As for the contradictions, while with one stroke of his pen he berates scale-free networks, in the next he praises the adaptivity of the World Wide Web, which, of course, is scale-free. The web, he says, is unstable enough to create unexpected innovations but orderly enough to learn from its failures and successes, and provides a shining example upon which other structures should be modelled. In addition, while he makes his opposition to modern capitalism abundantly clear, he praises market systems for their remarkable adaptivity! And while arguing for more bottom-up adaptive processes, he simultaneously calls for larger governments and more intervention on their part.

I conclude this review with a quote from the book which, to my mind, highlights the muddle-headed conclusions the author draws from his voyage through Roman history, panarchy, and the interesting theory of energy return on investment, and seems completely contrary to the bottom-up adaptive systems he argues we should strive for:

Any kind of new democracy must encompass not only communities, towns, cities, and societies, but humankind as a whole. In fact, it’s hard to imagine how we’ll prosper together on this tiny planet if we don’t eventually have some kind of democratic world government.

11
May

Anna and Will seem to be settling in nicely in Japan. They’ve just had an optical fibre connection installed: 100Mbps (in theory). Sweet! I guess we can expect some more regular blogging by Anna from now on (wink wink, nudge nudge).

07
Apr

Anyone who’s interested in the climate change debate (and I’m still of the opinion that there is a debate) should read this two-part paper published in the World Economics Journal at the end of last year. It’s a critical analysis of the Stern Review on the Economics of Climate Change, a document that has arguably done more than any other (save, perhaps for the various IPCC papers) to convince governments of the need to act on global warming. The first part covers the science (written by several climate change experts), and the second covers the economics. Readers of this weblog might be particularly interested in the following excerpt from the critique:

Section 3 is concerned with fundamental issues of scientific conduct and procedure that the Review fails to consider. Professional contributions to the climate change debate very largely take the form of published peer-reviewed articles and studies. It is widely assumed, in particular by governments and the Intergovernmental Panel on Climate Change (IPCC), that the peer review process provides a guarantee of quality and objectivity. This is not so. We note that the process as applied to climate science has tolerated gross failures in due disclosure and archiving, and that peer review is both too inbred and insufficiently thorough to serve any audit purpose, which we believe is now essential for science studies that are to be used to drive trillion-dollar policies.

I think this observation about peer-review processes in the climate science community probably holds true for many, if not most, scientific communities. I’ve certainly seen evidence of inbreeding and insufficient thoroughness within the small subset of the computer science community with which I’m involved. And, from my (still fairly limited) experience, due disclosure barely gets a look-in. For instance, the frequency with which authors are asked whether they’ve disclosed all their funding sources and correctly cited all their sources is very low in my (still fairly limited) experience.

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