Friday, April 20, 2012
Complaint about laptop keyboards
I don't like how laptops leave open, unused space below the keyboards. I prefer my old TRS-80 Model 100 in that regard. (Model 100 also had good battery life.) I've been told people like the empty space to rest their hands on. But typewriters didn't have any such space. I will admit that as someone who "hunts and pecks" I don't hold my hands the same way a touch typist does. (Like a numeric keypad a touch pad/trackpad would best be placed to the right of the keyboard.)
Hello World
I never write "hello world" programs. I just installed Python (and Prolog) on my Linux based netbook. Since any program can be built from sequences, loops, and decisions I tried Python out on:
a sequence of commands
a=2
b=3
c=a*b
print c
a simple loop
for x in range (0,4):
print x
and a simple decision structure
a=5
b=3
if a==5:
print b
else:
print a
With AI software I frequently try something like:
human(bob).
mortal(X):-human(X).
?-mortal(bob).
a sequence of commands
a=2
b=3
c=a*b
print c
a simple loop
for x in range (0,4):
print x
and a simple decision structure
a=5
b=3
if a==5:
print b
else:
print a
With AI software I frequently try something like:
human(bob).
mortal(X):-human(X).
?-mortal(bob).
Friday, April 6, 2012
Linear utility functions and assessment
When we assess job applicants, or employees, or rank grant applications we typically use a linear utility function. We take things like the number of years in teaching, the number of papers published, the number of talks given, etc., multiply by some weighting number, and sum up to a single numeric score. It is easy to show how poor an approximation such a linear model is likely to be. For a scientist or academic an IQ of 120 would be quite reasonable but an IQ of 60 would surely be hopelessly low. A linear model involving IQ is surely a poor model. A nonlinear model, with IQ raised to some power, would certainly be needed. When we use a linear model we are simply hoping the approximation is good enough.
An advantage to being an engineer II
I have previously described some advantages to doing engineering work rather than science (21 Jan. 2011). Another advantage to engineering is that the prior probability of succeeding in an engineering project can be higher than the prior probability of succeeding in a scientific investigation. This is because engineering projects are usually based upon more well established knowledge. Hence the higher prior probability.
Tuesday, April 3, 2012
Education reform
Programs like "no child left behind" expect too much. Learning is, in general, an NP complete problem. Learning will never be easy. Neither will it be cheap and all too often the reformers want it to be cheap.
Monday, April 2, 2012
The achilles heel of scientific pluralism
I advocate scientific pluralism (Scientific Pluralism, S. H. Kellert, et al, U. of Minn. Press, 2006) in both science and engineering (and in pretty much everything else I do, see my 26 Sept. 2010 blog post).
But one must maintain a strong skepticism. Most published research is erroneous (Why most published research findings are false, J. P. A. Ioannidis, PLoS Medicine, August 2005) and one can assemble huge "databases" of faulty results (see, for example, www.rexresearch.com). Just because we accept two or more different theories/models does not mean we can be any less skeptical in our work.
But one must maintain a strong skepticism. Most published research is erroneous (Why most published research findings are false, J. P. A. Ioannidis, PLoS Medicine, August 2005) and one can assemble huge "databases" of faulty results (see, for example, www.rexresearch.com). Just because we accept two or more different theories/models does not mean we can be any less skeptical in our work.
Science on twitter?
Some colleagues attempt to discuss their scientific work on twitter. While my publications are quite succinct, of my more than 150 blog posts only a very few are brief enough to be tweets. 140 characters is just too few. 280 is only a bit better. A link that would send you to a real blog would just be advertising. Just start at the blog in the first place.
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