Experimental Design: Sleep and Memory Retention

In a recent study, researchers were interested in examining the effect of sleep on memory retention. Participants were randomly assigned to two groups: one group was allowed to sleep for 8 hours, while the other group was given only 4 hours of sleep before they were tested on their memory of a list of words they had learned the day before. Based on this experimental design, answer the following:

Explain how the researchers have implemented an experimental design in this study. Include a discussion of the independent and dependent variables, control measures, and the importance of random assignment in your response.