This is my plan for tomorrow morning's Intro Stats class: (8:10-9:50)
I put four Excel spreadsheets on Blackboard: one with data re colleges and
universities, one with a cell phone survey data, and two re automobiles. I
will allow ten minutes for groups to create numeric and graphic analyses of
the data sets and present them briefly to the class. (review of types of
variables and appropriate numeric and graphic analysis)
I'll discuss the computation of standard deviation and Z scores and then do
an interactive application of these tools to four worksheets I will have
put on Blackboard and we will complete in class.
After a five minute break, I will introduce a "Friendly Observers" scenario
(24 people randomly assigned to 2 groups; one group performs a skilled task
and is told it will be observed and rewarded monetarily if it exceeds its
prior threshold performance; the other group does not have observers who
will also be rewarded if the performers exceed the threshold and only the
participants will receive a reward. Three persons in the first group
exceed the threshold, and eight in the second group do. The question is:
do vested observers have an effect on performance?)
One group in class will simulate the scenario using playing cards, one with
a random number table, one with a calculator random number generator, and
one with Excel's random generator. Groups will present a graphic of their
results, and we will discuss them without using the language of inference.
(We did Dolphin Therapy two weeks ago on the first day of class)
On Mon, Feb 2, 2015 at 12:34 AM, Allan Rossman <arossman(a)calpoly.edu> wrote:
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 93407arossman@calpoly.eduhttp://statweb.calpoly.edu/arossman/
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