Hi, Chris, Steve and all ---
Yes, the PRIMARY reason for "blocking" MIGHT be to 'REDUCE VARIATION'.
However, "selling statistics" or "getting students 'hooked'" during the
first-day contact
should be one objective. Students can easily become excited when they
become aware of the power they might have to "control for the
uncontrollable" if they can measure
those 'uncontrollables" and include them in the their statistical models.
Some stimulating discussions might be:
"Controlling the weather -- when you really can't"
"Controlling for student-characteristics differences when comparing
teachers' performance -- when you really can't"
Other applications can be created by students as topics for group
discussion.
Furthermore, not only can they become AWARE of the possibilities, but they
should be
given some practical experiences to use some of the powerful capabilities
BEFORE THEY GIVE
UP ON THEIR STATISTICS ENCOUNTERS.
If teachers would like to "sell statistics", then their students' FIRST
CONTACT WITH "BLOCKING" should be to CONTROL FOR THE UNCONTROLLABLE. They
can become aware of the PRIMARY purpose later, after they are "hooked" and
when they have obtained the concepts needed to understand the meaning of
"REDUCING VARIANCE".
But there is a RISK! If you make them AWARE of the possibilities your
bright students might become
"restless" if you don't give them some of the power to actually DO IT!
Of course, this is just the opinion of an "outlier".
:-)
Joe --
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Joe Ward Health Careers High
School
167 East Arrowhead Dr 4646 Hamilton Wolfe
San Antonio, TX 78228-2402 San Antonio, TX 78229
Phone: 210-433-6575 Phone: 210-617-5400
Fax: 210-433-2828 Fax: 210-617-5423
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http://www.ijoa.org/joeward/wardindex.html
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