Exercises
The default values of the parameters are:
Probability of success in Condition 1 = 0.6
Probability of success in Condition 2 = 0.6
N = 10 for both conditions.
- Using the default values, simulate one experiment. Calculate Chi Square
by hand and compare your results to those shown in the simulation. Click here
for the computational method.
- Again using these default values, what proportion of the time should the
Chi Square test be significant if the test were exact? Determine the proportion
of significant outcomes by simulation. Does the test appear to be exact or
approximate? Does Yate's correction for continuity improve the test?
- Find a set of parameters for which the Type
I error rate is too high for the uncorrected test.
- Try out a variety of parameter values and see if you think the correction
for continuity should be used as a general rule.
- A researcher is planning an experiment in which she believes that the population
proportion of successes in Condition 1 is 0.6 and the population proportion
in Condition 2 is 0.3. If the researcher wishes to have about an 80% chance
of finding a significant difference (assuming her beliefs about the population
are correct), what sample size should she use. Determine this for both the
0.05 and 0.01 significance levels.