Researchers are interested in the effectiveness of a particular treatment for insomnia. Fifty insomnia sufferers who responded to a newspaper ad are contacted, and each is given a pill with instructions to take it before going to sleep that night. The pill actually contains milk powder (a placebo). The participants are randomly assigned to receive one of two sets of instructions about the pill. One half of the participants are told that the pill will make them feel "sleepy," and the other half are told that the pill will make them feel "awake and alert." The next day the participants return to the lab and are asked to indicate how long it took them to fall asleep after taking the pill. The individuals who were told that the pill would make them feel sleepy reported that they fell asleep faster than the participants who were told the pill would make them feel alert.
Think about the concepts you have read about this week and how they apply to the study.
The assignment: (1�2 pages)
With the study in mind, please do the following:
Identify the independent and dependent variables. Indicate the number of levels in the independent variable and describe each level.
Indicate whether the research used a between-participants or a within-participants research design and explain how you concluded which type of design was used.
Suppose an ANOVA was conducted. Briefly explain in your own words what it would mean if the F was significant in this particular study.
When going to sleep, why would anyone want to take a pill that makes them feel "awake and alert"? I would also have a group that took no pill.
I have no idea of what concepts "you have read about this week." However, this should start you out:
An independent variable is the potential stimulus or cause, usually directly manipulated by the experimenter, so it could also be called a manipulative variable.
A dependent variable is the response or measure of results.
To answer these questions, let's break down the study and analyze the concepts involved:
1. Independent and Dependent Variables:
- The independent variable in this study is the set of instructions given to the participants about the pill's effects. It has two levels: "sleepy" and "awake and alert."
- The dependent variable is the participants' reported time it took them to fall asleep after taking the pill.
2. Research Design:
- The study used a between-participants research design. This conclusion can be drawn from the fact that the participants were randomly assigned to two different groups, each receiving a different set of instructions. This ensures that the two groups are distinct and independent from each other.
3. ANOVA and Significance of F:
- If an ANOVA (Analysis of Variance) was conducted and the F-value was found to be significant, it would indicate that there is a statistically significant difference between the mean reported time to fall asleep in the "sleepy" group and the mean reported time in the "awake and alert" group.
- In simpler terms, a significant F-value suggests that the instructions given about the pill's effects had a noticeable impact on the participants' reported time to fall asleep. It suggests that the expectation set by the instructions influenced their perception or experience of falling asleep.