Independent developer book reviews by and for practitioners

Most books on data analysis are focused on algorithms — giving you the statistical tools of the job, with instructions on what technique to use for different tasks and with different data sets. That isn't the approach that this Head First book takes — far from it. The approach adopted by author Michael Milton is to focus instead on what it is a data analyst does — it's the why rather that purely the how. Add to that the distinctive Head First approach — informal, light hearted and geared heavily around exercises for you to engage in — and you've got yourself a fairly unique proposition as far as data analysis books go.

The first and most obvious thing to point out is that this is not a book that is aimed at experienced analyst (though those who already walk the walk might enjoy dipping in anyway). The book is aimed squarely at the beginner — someone who is faced with the task of analysing some data but who doesn't have a systematic way of going about it. What the book provides the reader then is a gentle way into the field using common tools (mainly Excel and OpenOffice), worked examples and a chance to tag along with exercises, questions and answers, sample data and common scenarios.

Aside from specific topics such as hypothesis testing, regression, data cleansing and so on, the book brings out the point that much data analysis work is iterative, exploratory and that it needs to be utterly focused or it ends up being a black hole that leads nowhere (but with a lot of numbers along the way). [Continued]

The associative array, often called a Map or Hash Map, is one of the most useful data structures available to the programmer. Unlike a normal indexed array, the contents of an associative array are accessed via a ?key? rather than a numerical index. So, instead of having to keep track of where things are in an array, the programmer can assign a unique key to a value and then add the key, value pair to the array. Retrieving the value is just then a case of using the key. For example key value pairs could be names and ages: John, 34; Jane, 46; Ted, 102 etc.

In languages such as Java and C# there are entire families of associative arrays available via collections frameworks. In other languages such as Python, Ruby or Groovy the map is a basic part of the language. What about VBA? Well, it just so happens that there is a form of associative array called the Dictionary that VBA programmers can use. This tutorial will be using Excel as the application, but the same principles are available in Word, PowerPoint and anything else that uses VBA.

The first thing to do is to create a reference to the Microsoft Scripting Runtime, which is the DLL that contains the Dictionary (as well as the FileSystemObject). To do that we open Excel, hit F11 to get to the Visual Basic environment and then select References from the Tools menu. Navigate down through the list of available references and select Microsoft Scripting Runtime (\Windows\system32\scrrun.dll). Once that?s done the Dictionary is available for you to use in your code. [Continued]

This may be the shortest review in the history of TechBookReport and really it could be summed up with the advice to ignore this book until a new edition comes out. This edition is so riddled with errors that it's impossible for a beginner to make sense of the content. For example the reaction equations throughout the text are missing the arrows - you have to guess where they are by looking at the gaps between terms. The text mentions the double arrows often enough, so you know they ought to be in there somewhere… But these aren't the only errors, there are others scattered through the text. It destroys any trust you might have in the content. What's worse is that the publishers haven't bothered to put corrections on a web page where we can at least check out what the text is supposed to say.

Lots of books have typos and the occasional mistake, but such fundamental errors are unforgiveable. Where was the quality control? What kind of proofing process is in place? It just doesn't make sense that nobody noticed that all of the equations were lacking. The publishers have done the two authors a grave disservice. It's hard to say how good the content is because of it.

So, until there's a new edition with these errors corrected this is a book to avoid at all costs. [Continued]

Billed as a desktop quick reference on statistics, this is a book that is geared to developing statistical reasoning rather than simply listing statistical techniques or tables of figures. Aimed at students taking introductory stats courses, adults learning stats in a work-environment or those who are just interested in learning more about the subject. That's a fairly wide remit, and as we'll see it succeeds more in some areas than others.

The book is organised into four sections: introductory (which starts with basic concepts of measurement, introductory probability, descriptive statistics, research design, critiquing statistical analyses and data management); basic inferential statistics (introduction to sampling and hypothesis testing, the t-test, correlation, categorical data and non-parametric statistics); advanced techniques (the general linear model, analysis of variance, multiple linear and other regression techniques, principal components and other advanced techniques); and finally a section that looks at statistical analysis in different domains (business and quality improvement, medicine and epidemiology, education and psychology). The book rounds off with a series of appendices, including a chapter that looks at the main statistical software tools - from SPSS to SAS, R and even Excel. [Continued]

In addition to authoring a number of best-selling Java and XML books (including Processing XML With Java, Java I/O and Effective XML), Elliote Rusty Harold is also the seasoned webmaster of the Cafe au Lait and Cafe con Leche websites (specialising in Java and XML respectively). As such the day to day reality of having to maintain and update page upon page of HTML code is one that he is intimately familiar with. The sad fact is that web sites accrue cruft in the same way that software does. And how do you tackle de-crufting software? You refactor it. And, in the same way Harold suggests that web sites need refactoring too.

The approach that Harold outlines in this book is well-structured and can be implemented incrementally rather than requiring a big-bang approach. At the heart of it is the need to move towards standards based web sites. Specifically this means moving to XHTML and CSS, with a clear separation between structure and layout. And, as with software refactoring, the emphasis is on discrete steps that make changes without breaking the application (or web site).

Like other books on refactoring this one focuses very much on the concrete rather than the purely theoretical. [Continued]

Windows Vista Annoyances, Head First Statistics and lots more...