The math department recently purchased new learning software for their freshman math classes. The instructors want to use the learning software instead of a textbook. So they decide to study the effectiveness of the software. First they test the skills and concept mastery for a number of the freshman math students. Then they randomly divide the students into two groups. One group uses the learning software for a particular lesson and the other group uses the regular textbook. Then the instructors retest all of the students and compare the improvement in the skills and concept mastery for the two groups. What is the purpose of random assignment in this experiment? Check all that apply.

Options :

A.) To avoid bias

B. To control for confounding variables

C. To produce treatment groups with similar characteristics

D. To generalize the experiment results to all freshman math students

To avoid bias

To generalize the experiment results to all freshman math students

Step-by-step explanation:

One of the most common problems with statistical experimental research is the issue posed by bias. Either selection bias or assignment bias. Bias creeps into our experiment when one experimental group is more favored than the other. This means that the strategy employed is not totally random. In the experimetal design explained above, students were randomly assigned to group in other to avoid bias. This random assignment ensures that all samples have equal probability of being assigned to any of the two groups.

Randomized experimental designs also allows for making a good estimate of the population parameter fromnthe sample statistic