Psych 543 Quiz | Nov 19, 2002

Submit answers via e-mail to fraley@uic.edu

1. What is the difference between forward and backward inference?

2. What is a Type I error?

3. Write a brief program/script in S-Plus that simulates a situation in which you are measuring a continuous dependent variable in an experimental group (N = 10) and a control group (N = 10). Assume the means (10) and standard deviations (2) for both groups are equal in the population (i.e., assume the null hypothesis is true). (a) What mean difference between sample groups do you expect on average? (b) On average, how much will the observed mean difference between groups differ from the true mean difference? Send me your answers and your program.