HOMEWORK; WEEK 1

2.1, 2.3, 2.5, 2.6, 2.10, 2.12

2.1)	False. (Cannot say anything about the comparative safety
		b/c you need to know how much people fly by commuter
		airlines vs. scheduled carriers.  Then you can 
		compare rates.  Per aircraft mile flown, the scheduled
		carriers are safer than the commuter airlines.)

2.3)	No.  In the Salk trial, the parents who consented were on the
		whole better off than the parents who did not consent,
		and their children were more at risk to begin with (p.4).

2.5)	No. The data from the double-blind study are more reliable, 
		and suggest that the results from the single-blind
		were biased.

2.6)	Subjects who did not improve during the first part of the trial
	probably concluded that they were on the placeo (whether they
	were or weren't) and would be switched to the "real" medication
	during the second part of the trial.  This expectation caused
	them to improve - the placebo effect.

2.10)	a. Observational Study
	b. Yes
	c. Yes
	d. No - the gene would also have to be associated with 
		controlling behaviour by the mother (p.20)
	e. Mothers who see their children over-eating might react
		in a controlling way (rather than the other way
		around.)
	f. No.  Correlation/Association Does Not Equal Causation!!!


2.12)	False.  The conclusion does not follow.  This is just like
		the admissions study (p 17).  The Democrats may be
		concentrated in wards with low turnouts.  Here is
		an example, with only two wards.


			Democrats		Republicans
		#Voting  #Registered   %     ,  #Voting  #Registered  %

	Ward A  100	  1000        10%    ,    5        100        5%

	Ward B   60        100        60%    ,  500       1000       50%

               ----------------------------------------------------------

	Total	160	  1100        14.5%  ,  505       1100       45.9%