Skip to main content

Once upon and Algorithm - Martin Erwig ***

I've been itching to start reading this book for some time, as the premise was so intriguing - to inform the reader about computer science and algorithms using stories as analogies to understand the process.

This is exactly what Martin Erwig does, starting (as the cover suggests) with Hansel and Gretel, and then bringing in Sherlock Holmes (and particularly The Hound of the Baskervilles), Indiana Jones, the song 'Over the Rainbow' (more on that in a moment), Groundhog Day, Back to the Future and Harry Potter.

The idea is to show how some aspect of the story - in the case of Hansel and Gretel, laying a trail of stones/breadcrumbs, then attempting to follow them home - can be seen as a kind of algorithm or computation and gradually adding in computing standards, such as searching, queues and lists, loops, recursion and more.

This really would have been a brilliant book if Erwig had got himself a co-author who knew how to write for the public, but sadly the style is mostly heavy academic, so the cleverness is rather wasted. Sometimes this comes across in labouring points and at others in spending a lot of effort on what is little more than defining labels for things, rather than providing useful information and context for the reader. It's not that there's not a lot of good material in there, just that it's hard work to dig it out, where I'm sure the whole idea of using the stories was to make it more approachable.

Part of the problem is that the stories themselves don't always work very well as an analogy for what's happening in the computation. So, for example, in the section dealing with sorting he comes up with the task of sorting the tasks and places that Indiana Jones needs to deal with to find the Lost Ark. The unsorted list includes the likes of: disc, sunbeam, Marion and Nepal. The algorithm used involves finding the 'smallest' element... which somehow we are supposed to instantly see is Nepal. Using numbers would not have been so well-linked to the story, but at least it would have made some sense to the reader.

Perhaps the low point is the section that uses a part of the song 'Over the Rainbow' (giving us a tenuous story connection to The Wizard of Oz) to examine language and meaning. If you aren't familiar with musical notation, I'm not sure it's a very helpful analogy... and if you are, some of the ways it's used (particular the assertion of what bars are for) doesn't entirely make sense.

I was a professional programmer for a number of years, but without a computer science background. So I was very familiar with how to do this stuff, but knew nothing of the theory behind it. As such, I found the content of the book really interesting - and the story idea should have made it doubly brilliant - but the execution meant that it didn't deliver anywhere near as well as it could have. Even so, there's a lot to savour, and it's definitely worth persevering to get a feel for why computer programs involve far more than just 'cutting code.'


Hardback:  

Kindle:  

Using these links earns us commission at no cost to you

Review by Brian Clegg

Comments

Popular posts from this blog

The Laws of Thought - Tom Griffiths *****

In giving us a history of attempts to explain our thinking abilities, Tom Griffiths demonstrates an excellent ability to pitch information just right for the informed general reader.  We begin with Aristotelian logic and the way Boole and others transformed it into a kind of arithmetic before a first introduction of computing and theories of language. Griffiths covers a surprising amount of ground - we don't just get, for instance, the obvious figures of Turing, von Neumann and Shannon, but the interaction between the computing pioneers and those concerned with trying to understand the way we think - for example in the work of Jerome Bruner, of whom I confess I'd never heard.  This would prove to be the case with a whole host of people who have made interesting contributions to the understanding of human thought processes. Sometimes their theories were contradictory - this isn't an easy field to successfully observe - but always they were interesting. But for me, at least, ...

The AI Paradox - Virginia Dignum ****

This is a really important book in the way that Virginia Dignum highlights various ways we can misunderstand AI and its abilities using a series of paradoxes. However, I need to say up front that I'm giving it four stars for the ideas: unfortunately the writing is not great. It reads more like a government report than anything vaguely readable - it really should have co-authored with a professional writer to make it accessible. Even so, I'm recommending it: like some government reports it's significant enough to make it necessary to wade through the bureaucrat speak. Why paradoxes? Dignum identifies two ways we can think about paradoxes (oddly I wrote about paradoxes recently , but with three definitions): a logical paradox such as 'this statement is false', or a paradoxical truth such as 'less is more' - the second of which seems a better to fit to the use here.  We are then presented with eight paradoxes, each of which gives some insights into aspects of t...

Einstein's Fridge - Paul Sen ****

In Einstein's Fridge (interesting factoid: this is at least the third popular science book to be named after Einstein's not particularly exciting refrigerator), Paul Sen has taken on a scary challenge. As Jim Al-Khalili made clear in his excellent The World According to Physics , our physical understanding of reality rests on three pillars: relativity, quantum theory and thermodynamics. But there is no doubt that the third of these, the topic of Sen's book, is a hard sell. While it's true that these are the three pillars of physics, from the point of view of making interesting popular science, the first two might be considered pillars of gold and platinum, while the third is a pillar of salt. Relativity and quantum theory are very much of the twentieth century. They are exciting and sometimes downright weird and wonderful. Thermodynamics, by contrast, has a very Victorian feel and, well, is uninspiring. Luckily, though, thermodynamics is important enough, lying behind ...