The following table shows the average knowledge of safety practices related to chemical leak emergencies at a chemical plant, based on a sample of 221 chemical plant employees.
The employees were given a knowledge test at the time they were hired. They were then given the test again at multiple time points after their original hire date. They were trained on safety procedures at 3 months posthire.

The data presented here are sometimes called a time-series quasi-experimental design that can be used in evaluating the safety training program.

Questions 

1. These data indicate a slight increase in the employees’ mean performance on the emergency safety procedures knowledge test at baseline and for the first 2 months after they are hired (prior to the online safety training).
What are some possible reasons for this effect?
2. There is a “bump” in the employees’ performance on the knowledge test immediately after they are trained. However, their knowledge then begins to decline over the next several months. What are some possible reasons for this effect?
3. Why would employees’ knowledge in this particular domain decline, even though they are on the job? Put differently, wouldn’t their working on the job continue to maintain their knowledge of emergency safety procedures? Why or why not?
4. Safety is a top priority in companies such as this one. If you were a manager, what could you do to remedy this decline in knowledge level among employees posttraining?

Transcribed Image Text:

TIME OF HIRE/ BASELINE JOB KNOWLEDGE TEST SCORE (OUT OF 100) 55 1 MONTH 2 3 4 6 9 12 POSTHIRE MONTHS MONTHS MONTHS MONTHS MONTHS MONTHS POSTHIRE POSTHIRE POSTHIRE POSTHIRE POSTHIRE POSTHIRE ONLINE SAFETY TRAINING 60 64 88 80 76 74