1. Using the default settings, click "simulate" and see what the type I error rate is. It should be close to 0.05. Try running more simulatons by pressing the "simulate" button again. If the simulations are done quickly, try setting the number of simulatons to 10,000 before pressing the "simulate" button.
   
2. Examine the effect of non-normality. Give both distributions a slight skew. Do at least 10,000 simulated experiments. Note how the type I error rate varies from 0.05 (if at all).
   
3. Repeat Step 2 using 15 subjects per group instead of the default of 5.
   
4. Make both distributions normal but make the variance of the second distribution much bigger than the first. Find the type I error rate for 5 subjects per group and then for 20 subjects per group.
   
   
5. Try different combinations of skew and heterogeneity of variance and examine the effects on the type I error rate.
   
   
6. Investigate the effects of the combination of unequal sample sizes and homogeneity of variance. Give one population a standard deviation of 1 and the other a standard deviation of 3. Then make the sample sizes unequal. For one set of simulations, make the sample from the population with a standard deviation of 1 larger than for the other sample. Then try it the other way.