Table of contents
- 1. Intro to Stats and Collecting Data55m
- 2. Describing Data with Tables and Graphs1h 55m
- 3. Describing Data Numerically1h 45m
- 4. Probability2h 16m
- 5. Binomial Distribution & Discrete Random Variables2h 33m
- 6. Normal Distribution and Continuous Random Variables1h 38m
- 7. Sampling Distributions & Confidence Intervals: Mean1h 3m
- 8. Sampling Distributions & Confidence Intervals: Proportion1h 12m
- 9. Hypothesis Testing for One Sample1h 1m
- 10. Hypothesis Testing for Two Samples2h 8m
- 11. Correlation48m
- 12. Regression1h 4m
- 13. Chi-Square Tests & Goodness of Fit1h 20m
- 14. ANOVA1h 0m
1. Intro to Stats and Collecting Data
Intro to Stats
Problem 1.r.22
Textbook Question
200 students volunteer for an experiment to test the effects of sleep deprivation on memory recall. The students will be placed in one of five different treatment groups, including the control group.
Explain how you could design an experiment so that it uses a completely randomized design.

1
Define the experimental groups: Clearly identify the five treatment groups, including the control group. For example, the groups could represent different levels of sleep deprivation (e.g., 0 hours, 2 hours, 4 hours, 6 hours, and 8 hours of sleep).
Randomly assign participants: Use a randomization method (e.g., a random number generator or drawing lots) to assign each of the 200 students to one of the five groups. Ensure that each group has an equal number of participants, if possible, to maintain balance.
Control for confounding variables: Ensure that all other factors (e.g., age, gender, prior sleep habits) are evenly distributed across the groups by relying on the randomization process. This helps to isolate the effect of sleep deprivation on memory recall.
Administer the treatments: Implement the sleep deprivation conditions for each group as planned. For example, the control group might get 8 hours of sleep, while the other groups receive progressively less sleep.
Measure the outcome: After the treatment period, test all participants using the same memory recall test under identical conditions. Record and analyze the results to determine if there are significant differences in memory recall between the groups.

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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Completely Randomized Design
A completely randomized design is an experimental setup where all subjects are assigned to treatment groups purely by chance, ensuring that each participant has an equal opportunity to be placed in any group. This method helps eliminate bias and allows for a fair comparison of the effects of different treatments, as it minimizes the influence of confounding variables.
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Random Assignment
Random assignment is the process of allocating participants to different treatment groups in a way that is determined by randomization, such as using random number generators or drawing lots. This technique is crucial in experimental design as it helps ensure that the groups are comparable at the start of the experiment, thus enhancing the validity of the results.
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Control Group
A control group is a baseline group in an experiment that does not receive the treatment being tested, allowing researchers to compare the effects of the treatment against a standard. This group is essential for determining the effectiveness of the treatment, as it helps isolate the impact of the independent variable on the dependent variable, in this case, memory recall.
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