The director for training at a company that manufactures electronic equipment is interested in determining whether different training methods have an effect on the productivity of assembly line employees. One of his employees who is tasked with testing this assumption randomly assigns 42 recently hired employees into two groups of 21, of which the first receives a computer assisted, individual-based training program and the other receive a team-based training program. Upon completion of the training, the employees are evaluated on the time (in seconds) it took to assemble a part. The results are as follows:
Computer-Assisted Team-Based
21.3 20.7 21.8 24.4 18.7 19.3
14.1 16.1 16.8 15.6 18.0 21.7
14.7 16.5 16.2 30.7 23.7 12.3
16.4 18.5 16.7 16.0 13.8 18.0
19.3 16.8 17.7 20.8 17.1 28.2
19.8 19.3 16.0 20.8 24.7 17.4
17.7 17.4 16.8 20.1 15.2 23.2
The director is an avid proponent of computer-assisted training and asserts even before the research study that the team-based training program will produce not only different, but higher times to assemble than the computer-assisted training program.
a) What would the researcher conclude with these data? (Assume a maximum type 1 error of 5% and state any assumptions you have to make).
b) What is the probability of a type 1 error in this situation? What does it mean?
c) Write a few sentences describing the findings, which will be presented to the director. What should you advise him or her?