Happy
Groundhog Day!
I continue to find it inexplicable that neither private colleges
nor public
universities see fit to cancel classes out of respect for this
august
occasion. But this year I've decided to try to make the best of
this
lamentable oversight, and I need your help!
I think it might be fun to ask introductory statistics teachers
to compare
notes on what's happening in their classes on one particular
day. What
better day than Groundhog Day for revisiting the same question
over and over,
and over and over, and over and over, from multiple
perspectives?
I'm writing this after Groundhog Day has officially begun in
Punxsutawney,
Pennsylvania, but it's shortly after 9pm on Super Bowl Sunday
here in
California. So, to get the ball rolling on this whimsical idea
(I
strongly prefer the word "whimsical" to "silly" in this
context), I'll use
future tense to anticipate what will happen in my class on
Monday. I plan
to be sound asleep when Punxsutawney Phil makes his celebrated
prognostication. (Too much information: Thirty years ago I did
indeed
make the trek to Gobbler's Knob with my future bride before
sunrise on February
2, but I won't be up so early or anywhere near Punxsutawney this
year!)
My introductory students and I in STAT 217-09 at Cal Poly will
begin the fifth
week of our ten week term on February 2 by finishing up a
discussion of
principles of well-designed experiments.
We’ll discuss a study conducted at Harvard about whether
students spend
$50 differently depending on whether they’re told that it’s a
“tuition rebate”
or “bonus income.” Then
we’ll consider one
of the first studies of the drug AZT for reducing
mother-to-child transmission
of HIV. We’ll culminate
this discussion
by collecting some in-class data on a very simple randomized
experiment
investigating whether grouping of letters can affect memory.
All students
will receive the same 30 letters in the same order, but some
will find convenient,
recognizable three-letter groupings and others will see more
irregular
groupings of letters.
Then
I expect to have time to introduce a study about whether
swimming with dolphins is beneficial to patients who suffer from
clinical
depression. We'll discuss the design of the study and do a
quick
exploration of the 2x2 table of results, setting the stage for
simulating a
randomization test to assess whether the difference between
success proportions
in two treatment groups is statistically significant. Carrying
out this
simulation in class, using cards and then an applet, will have
to wait until
February 3 when the excitement of the momentous day has passed.
(Or who
knows, perhaps my students and I will find when we awake on
Tuesday that we are
destined to magically relive Monday again and again...)
Please indulge me in this fanciful exercise by replying to this
Simulation-Based
Inference listserv with a description of what happened, or will
happen, in your
introductory statistics class on Groundhog Day 2015. Maybe we
statistics
teachers will learn something interesting by exchanging this
information and
reflecting on the variety of responses. Even
if not, we can honor the grand tradition of Groundhog Day by
engaging in a
substantially less grand but only marginally more silly (oops, I
mean
whimsical) one.
With best wishes for the special day and for an early spring (to
those of you who
must endure winter),
Allan Rossman
-- Allan J. Rossman Professor and Chair Statistics Department Cal Poly San Luis Obispo, CA 93407 arossman@calpoly.edu http://statweb.calpoly.edu/arossman/