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Up: 7 Power and Sample
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Index
 Change the example program to obtain the expected for
the test for additive genetic effects. Find out how many pairs are
needed to obtain significant estimates of in 80% of all
possible samples.
 Explore the effect of power of a particular test of altering the
proportion of MZ and DZ twins in the sample.
 Show that the change in expected is proportional to the
change in sample size.
 Obtain and tabulate the sample sizes necessary to detect a
significant when the population parameter values are as
follows:


0.10 
0.00 
0.30 
0.00 
0.60 
0.00 
0.90 
0.00 
In what way do these values change if there are shared environmental
effects?
 Show that with small sample sizes for the number of pairs in
each group, some bias in the chisquared is introduced. Consider
whether or not this may be due to the part of the maximum
likelihood loss function (Equation on
page ).
Next: 8 Social Interaction
Up: 7 Power and Sample
Previous: 5 Loss of Power
Index
Jeff Lessem
20020321