If you're interested in something of a primer on the subject via their use (the global warming hoaxsters, that is) of statistical models, etc., you would be well advised to check out this post from Iowahawk.
Given the enormous economic stakes involved, you might think the media would have some spent a little time explaining the models underlying the hockey stick. Ha! Silly you. Whether it was a matter of ideological sympathy or J-school stunted math skills, press coverage has generally stuck to the story that there's an overwhelming scientific consensus supporting AGW. As proven by brainiac scientists with massive supercomputers running programs much too complex for your puny simian mind.
Au contraire! The climate reconstruction models used by Mann, et al. are relatively simple to derive, don't take a lot of data points, and don't require any special or expensive software. In fact, anybody with a decent PC can build a replica at home for free. Here's how:
Stuff you'll need
1. A computer. Which I assume you already have, because you're reading this.
2. The illustrative spreadsheet, available as an Open Office Calc document here, or as a Microsoft Excel file here. Total size is about 1mb.
3. A spreadsheet program. I highly encourage you to use Sun's Open Office suite and its included Calc spreadsheet -- it's free, very user friendly and similar to Excel, and it's what I used to create the enclosed analysis. You can download and install Open Office here. You can do all of the examples in Excel too, but you'll also need to download an additional add-on (see 4 below)
4. A spreadsheet add-in or macro for principal components analysis. Open Office Calc has a nice one called OOo Statistics which can be download and installed from here. This is the macro I used for the enclosed analysis. If you're using Excel, you'll have to find a similar Excel add-in or macro for principal components analysis. There are several commercial and free versions available.
Okay, ready? Now let's start reconstructing. Open the illustrative spreadsheet and follow the bouncing ball.
Mind you, I haven't gone through it (he suggests you set aside 30-to-60 minutes at a minimum) -- I hope to do so sometime this week -- but I do trust that it will be quite illuminating.
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