Archive for the ‘Reviews’ Category

First thoughts on the Kindle

Monday, December 28th, 2009

Being in the UK I’m obviously late to the Kindle party since they only became available here a few months ago. I got mine a few days ago (as a Christmas gift from my wonderful parents), and I’m excited enough to write about it here even if it’s all been said before.

I won’t say too much about the physical device itself, which functions very well. The e-paper screen is a pleasure to read from. The slightly reduced contrast means it’s tough in very dim light, but the trade-off of being able to read in bright sunlight is well worth it. The inclusion of a qwerty keyboard is a real marmite feature, but on balance I’m glad it’s there.

What really excites me about the devices is its potential to change the way I read. In the past I’ve left a trail of half-completed books in my wake, as I’ve never had the right one with me. Sooner or later I’d forget where I was in a book or even that I was reading it in the first place. If nothing else, the Kindle works well as a way of centralising my collection and tracking where I am with each one. Could I do the same with a few cheap bookmarks and a large sack to carry the books? Kind of, but the point is that I never did do that.

The built-in mobile phone circuitry that supports “whispernet” (global wireless delivery of books) looks on paper like massive over-engineering, since I purchase books far less frequently than I sit down at a computer. However, it changes the nature of the device from a portable book collection to a portable library, and that starts to feel like something out of a culture novel (the series of science fiction stories set in a high-technology utopia.)

Whispernet really comes into its own for newspapers and magazines, which benefit especially from arriving with you fast and effortlessly, and from old issues not taking up space. At the moment the catalogue of magazines is small and many suffer from the lack of graphics, but there are already some good titles that are very keenly priced. If I could transfer my subscription to The Economist to Kindle I might never read a paper magazine again.

One of the most overlooked things about newspaper and magazine delivery is its potential as a monetisation platform. Because it’s linked to your Amazon account, you can pay large or small amounts for content with ease. It may seem odd to say that I like having to pay for content, but he who pays the piper calls the tune. If I want something, I’d rather pay for it than hope that some advertiser values my eyeballs highly enough to pay for it on my behalf.

Using an electronic format essentially kills the second-hand market: since data doesn’t get worn out like a paper book does, resale of e-books by customers would compete unacceptably with new sales. Therefore Amazon has no choice but to prevent resale from happening. I don’t have a problem with this, provided that publishers recognise it and price their books accordingly. Second-hand sale of a book (whether for money or swapping in an informal economy) helps to defray the high cost of acquiring new books (at least part of which is in printing cost, and cross-subsidising printing of unsuccessful books).

In this sense, a Kindle book is less valuable than a brand-new hardback, since it has zero resale value. In the case of back-catalogue books it is also competing against virtually free copies of the dead-tree version from charity shops or Amazon Marketplace, which further lowers the price I’m prepared to pay. I suspect that the publishers who realise this and price accordingly will benefit.

One last thing about copyright: I don’t like the Digital Rights Management (DRM) of the Kindle. DRM is the technology that binds a copy of a book to a particular physical device, preventing you from lending the book to a friend or using it on an e-book reader not made by Amazon. It’s not unduly restrictive in everyday use, but the prospect of buying my entire collection again if Sony wins the format war is a bit of a downer.

However, I think the best way to ensure DRM goes away is to back up my voice with my wallet. DRM on music is on its way out, and this is not because of the people who forcibly broke DRM, but because the iTunes store proved that there was a market of people who were prepared to pay money and play by the rules. Adhering to the spirit of copyright when safeguards were in place gave the industry confidence in a way that arguing over the letter of the law never did.

Book Review: SQL and Relational Theory

Tuesday, December 1st, 2009
Front cover of the book "SQL and Relational Theory"

The first thing to know about SQL and Relational Theory is that it’s largely a retread of Chris Date’s previous excellent book Database in Depth. The latter is a favourite of mine: extremely readable, yet with enough theoretical clout to change the way I looked at databases forever. The new volume carries over large chunks of the text from the older one, with some minor tweaks. As the name suggests, it brings in substantial additional material to link relational theory in with SQL, the only practical implementation of the model in current use.

The front cover of "Database in Depth"

In the preface, Date explains that the motivation for the new book was the realisation that practitioners weren’t able to figure out for themselves how to apply his theoretical ideas within SQL. Clearing up this difficulty is an admirable goal, and illustrates well that Date’s approach is practical and not meant as ivory-tower theory, but I can’t help but wonder if one of the reasons he didn’t state was that books sell better with ‘SQL’ in the title.

The additional material has resulted in a book that is roughly twice as long. This isn’t a problem in itself, though it does spoil one of the things I loved about “In Depth”: that it could be read in a couple of evening’s work by a sufficiently motivated person. The importance of making a book light enough that you can sit and read it on the sofa without looking like a database nerd should not be understated.

The prose remains clear and readable, and strikes a nice balance that makes it approachable to relative beginners while avoiding ever sounding patronising. Date’s style is precise to a fault, and some people will find it needlessly pedantic; nevertheless, there isn’t any pointless pedantry here, and if you stick with it you’ll learn why subtle distinctions need to be made.

So how useful are the new insertions on SQL? I find it difficult to tell. On the one hand, it makes it much easier to relate the ideas in this book to discussions of theory that actually occur in the real world, since SQL is the lingua franca. In the old book, it was certainly annoying to have all the examples written in Tutorial D, without a real specification of how the language works. On the other hand, Date’s examples in this book are still in a mythical beast called “Standard SQL”, of which no practical implementation exists. What is good practice in standard SQL might be impossible in your chosen implementation, or there might be a better way to achieve the same thing.

It’s certainly worth buying one of the two books here, but the choice of which is not as obvious. If you already own “In Depth”, the updated version probably isn’t worth buying. If you don’t, then “SQL and Relational Theory” is the thing to buy, unless you’re after a lighter and more portable read.

Book review: Head First Statistics vs. The Manga Guide to Statistics

Wednesday, November 25th, 2009

Front cover of the Manga Guide to StatisticsStatistics is a subject that most people have less understanding of than they ought to, not least because it’s usually such a dry topic. As Zed Shaw pointed out, the lack of understanding of statistics is something of a blind spot for programmers, who tend to think of themselves as numerically proficient but often dismiss statistics as unimportant “stamp collecting” for people who can’t do “real maths”.

When I came across two books recently that try to make the subject more fun and approachable, I was initially quite sceptical. In my opinion, the main problem with statistics is not that people don’t spend time trying to learn it, but rather that they don’t properly comprehend the underlying principles. Too often teachers seem to be trying to make it more approachable by leaving out the mathematics, leaving just a series of “black box” techniques into which the student plugs the numbers. The problem with this is that it’s easy to plug numbers into the wrong black box.

Head first statistics Front cover

The Manga Guide to Statistics tells the story of Rui, a young girl who takes a course on statistics in order to impress an attractive teacher. The reader learns through Rui’s eyes as we observe a series of lessons. Though Rui lacks interest in the topic, she seems intelligent and the teacher strikes a good tone that avoids ever being patronising. The characters make for an entertaining read, and unlike “Head First”, the jokes actually made me laugh.

Of course, all this is for naught if the book doesn’t teach the concepts of statistics. Thankfully (and somewhat surprisingly to me), the answer is that it teaches the topic rather well. The main downside to the manga style is that information density is very low, and plenty of technical details are sketched or glossed over entirely. One positive side to this is that omitting details makes the principles stand out more clearly. This certainly won’t be your only book on statistics, but as an introduction it’s an engaging and memorable one.

Engaging and memorable are two adjectives that ought to apply to “Head First” as well, but I’m less convinced by this one. It strikes a chatty, informal tone with plenty of simplified examples, diagrams and other visual aids. A key part of its approach is to express the same idea several times in different forms, the effect of which varies between useful and infuriating depending on whether you were having trouble with the concept. Unlike other Head First titles, I found the tone positively patronising at times.

One obvious difference from the Manga Guide is the sheer volume of information presented. It goes into a lot more depth on graphing, probability and combinatorics, among other things. The pages are somewhat more information-dense, but even so it runs to a massive 677 pages (roughly equivalent to Schneier’s Applied Cryptography, if that gives you any idea). In terms of topics covered you won’t be left wanting, though the format doesn’t make a good reference book.

If you’ve learned statistics before and just need a refresher, the Manga Guide makes a good change of pace even if (or perhaps especially if) you wouldn’t normally read manga. I could certainly recommend the Head First book if you have struggled with learning statistics in other books and want to take things slowly, and if you don’t like the idea of switching to a “real” textbook once you’ve finished with the introductory material.