Final answer:
To test whether workers can deactivate a machine as quickly with their left hand as with their right, design a controlled experiment with randomized assignment of tasks using response time as the primary measure.
Step-by-step explanation:
To design an experiment to determine if workers can deactivate an industrial machine as quickly with their left hand as with their right hand, one must establish a controlled environment where a group of workers can test their response times. The experiment would involve two main activities for each participant: activating the emergency shutoff switch with the right hand and then with the left hand. Response times should be measured and recorded accurately.
The role of randomization in this design is crucial to avoid bias. Workers would be randomly assigned to perform the task with either hand first, ensuring that hand fatigue or learning effects do not influence the outcome. A randomized control trial would involve at least two groups: one group uses their right hand first, followed by their left, while the other group does the opposite.
Statistical analysis would then compare the average response times for each hand. It is important to keep all other variables constant, such as the type of machinery, the ergonomic setup around the shutoff switch, and the time of day when the experiment is conducted. This controlled approach ensures that the difference in response times, if any, is due to the hand used rather than external factors.