| Hand in Friday:
Hand in answers to these questions on the "Placebo Effect" article (outside my door/on reserve): a) Give two examples of the placebo effect b) What do researchers believe causes the placebo effect? - - - - - - - - - - - - - - - - - - - - - - - Design of experiment: All from Moore p. 200, 3.46 experiment? p. 187, 3.32 sickle cell p. 188, 3.34& p. 209 3.70 chemical reaction (randomize order) Also: Does this experiment have a Control/Baseline group? p. 192 3.37 child care, recruitment(randomize) Use a diagram like those on pp. 190-1 to show your design. - - - - - - - - - - - - - - - - - - - - - - - Control, randomization, replication p. 194 3.38 - - - - - - - - - - - - - - - - - - - - - - - Cautions (blinding, lack of realism) p. 196 3.42 pain reliever p. 202 3.55 placebo effect p. 208 3.75 reading medical jl - - - - - - - - - - - - - - - - - - - - - - - - - - - - PostponeSignificance p. 195 3.40 = = = = = = = = = = = = = = = = On a separate sheet: Prep for ch. 4: Do p. 216, 4.4 spinning penny Spin a penny 50 times, keeping track of Heads or Tails. Bring to class # of heads , #of spins, proportion that came up heads (# of heads divided by # of spins) A. Do this: Use the random number table in your book to pick 25 digits from 0,1,2,3,4,5,6,7,8,9. Do it like this: decide on a direction, up, down, across. Then close your eyes and put your fingertip (or pencil tip) blindly into the random number table. Open your eyes and start going from that point in your chosen direction till you've gone through 25 digits. Tally them as we did in class with the digits you "picked". Bring tally to class. 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| |
Read, to discuss
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Optional
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Homework questions?
"A Million Random Digits "
Literary Digest poll,
narrative
Design of Experiments: go to Day
19
then
HW: Placebo effect article:
a) Give two examples of the placebo
effect
b) What do researchers believe
causes the placebo effect?
Usually an experiment treats the placebo effect as a confounding
variable, and is designed so placebo effect will work equally
on all groups. There is no attempt to measure the
placebo effect. ("All" drug studies.)
PMS/acupuncture:
Acupuncture (wrong) vs. Acupuncture (right).
Sometimes an experiment deliberately tries to measure the
placebo effect (as in the article).
Acupuncture (wrong) vs.
Music.
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Start here Friday
Statistical Significance
p.194: An observed effect so large that it would rarely occur by chance
(assuming no real difference in treatments) is called "statistically significant".
"So large", "rarely", "by chance" will be defined and quantified in
Ch. 6.
Example: Suppose 95% of the subjects
had their headaches cured by treatment 9 and only 25% by treatment
1 (placebo). IF the medicine in fact did "no good" that would be
a very unlikely outcome. So we will say the difference in headache
cures between treatment 1 and treatment 9 is "statistically significant"
and be inclined to believe the medicine "works".
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