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August 26, 2005
Daily affirmation: "Matrix algebra is my friend!"
Non-negative definite matrices are also called "positive semi-definite" matrices...
I've been reading a bit about matrix algebra lately. Notice I said reading and not learning. There's a lot in mathematics that I just don't grok. I definitely feel like a non-native speaker. I wonder if people who are really good in mathematics have trouble understanding other things - things that I may be fairly good at - and if they feel as completely disoriented as I do when I'm trying to understand terms like determinant, orthogonal, and classical adjoint.
The reason for this self-flagellation is not so much directly related to my dissertation, but to improve myself as a methodologist. You see, matrix algebra is the foundation for regression analysis. Regression is used a lot in epidemiology to predict associations between exposures and outcomes or diseases. My problem is that I have a growing concern that methods like regression are misused - that they are applied in the wrong instances and leave the epidemiologist with a false confidence in the results.
So, I'm going back and reviewing regression from scratch. I'm reading a new book by David Freedman, a well-known statistics professor at UC Berkeley, and someone whom I've heard to be critical of how certain statistical tools are used in practice. I was heartened to read in the book's preface:
Much of the discussion [in this book] is organized around published studies... Some may find the tone of the discussion too skeptical. If you are among them, I would make an unusual request: suspend belief until you finish reading the book. (Suspension of disbelief is all too easily obtained, but that is a topic for another day.) [Emphasis added]
I'm looking forward to reading what he has to say. For now, it's back to
If G is non-negative definite rather than positive definite, that is, x'Gx = 0 for some x ≠ 0, then G is not invertible...
Posted by rigd0003 at 3:30 PM | Comments (1)
August 25, 2005
Scientists engaging in public discourse
 Image: CHRISTIAN DARKIN |
I've not posted in a while. I've been enjoying summer and doing a lot of reading - both for personal pleasure and professional progression.
Recently, I picked up the latest issue of Scientific American that had been sitting on my coffee table under a pile of other "to be read" material. The September issue (delivered in August, according to the special space-time and logic that dictates current magazine publication) is devoted to environmental sustainability and global problem-solving.
One of the things I most enjoy about SciAm is the opening Editorial, called "SA Perspectives," that sets the tone for the issue and makes scientific comment on current events. This month's Perspective particularly resonated with me. The editors encourage scientists to use their technical judgement to help society "navigate the shoals ahead." They acknowledge the danger of letting personal ideology steer research and narrow interpretation, but the greater danger is to disengage completely from public discourse.
Some critics, though, are unconcerned with philosophical debates about what scientists should or shouldn't do. Their complaints boil down to: I don't agree with what you're saying, and rather than engage with it, I will deny your legitimacy to say it. Sadly, that has become the dominant rhetorical strategy in the country today--one that will only make it that much harder to address the challenges of the coming decades.
I have seen this tactic often: scientists dismissed as talking heads. Sure, there are crack-pots and zealots in science. But unless we do something to change the current course, science will be marginalized as just another opinion and not as the beautiful tool for knowledge that it is.
Posted by rigd0003 at 11:39 AM | Comments (1)
August 17, 2005
Wikibooks - open content textbooks
Wikipedia and their parent foundation, Wikimedia, continue to impress me with their innovations in teaching and sharing information.
Now, as another boon to lovers of learning, I've just come across WikiBooks, Wikimedia's open content textbooks. And just like their encyclopedia, these textbooks are open to edits and additions.
· You can learn Spanish, Celtic Irish, or Klingon (no content on the Klingon yet);
· You can learn "How to Build a Computer", which won their Book of the Month Award;
· What about robotics, Shakespeare, or making armor?
· They even have children's books in their Wikijunior section.
Happy reading!
Posted by rigd0003 at 10:49 AM | Comments (0)
August 4, 2005
My thesis will never be this cool...
One of the great things about the Internet is that it's a perfect showcase for how creative people are. I just found another example courtesy of Salon's Audiofile.
What started out as Baba Brinkman's Honors Thesis has turned into an interesting literary tribute. Brinkman's The Rap Canterbury Tales is a translation of sorts from Chaucer's work into a rap/hiphop rhyme.
I think it's a great example of using academic skills in new and exciting ways. Brinkman has used his knowledge of Medieval literature and strong belief in hiphop lyrics as poetry to translate Chaucer's words not just into modern English, but into the language of hiphop. There's a example of his translational style here.
I'm not a fan of rap or hiphop, but I still think this is a very cool idea.
Posted by rigd0003 at 5:13 PM | Comments (0)