In: Statistics and Probability
Dr. Kovaleski is interested in examining whether quantity of sleep impacts problem solving ability. To test problem solving ability, the research team gave participants a puzzle and measured how long it took participants to solve the puzzle in minutes. A group of participants were instructed to sleep 5 hours and then solve the puzzle in the morning. Then the same participants were instructed to sleep 7 hours and then solve a different puzzle in the morning. Then, participants were asked to sleep 9 hours and then solved a third puzzle in the morning.
5 hours |
7 hours |
9 hours |
6 |
4 |
6 |
8 |
3 |
1 |
9 |
5 |
3 |
6 |
6 |
6 |
5 |
2 |
1 |
Answer the following questions and compute the Repeated Measures One Way ANOVA for the data provided above. For this example, assume that alpha is 0.05.
1. What is the research question?
Using Excel, go to Data, select Data Analysis, choose Anova: Single Factor at alpha = 0.05
ANOVA | ||||||
Source of Variation | SS | df | MS | F | P-value | F crit |
Between Groups | 32.93 | 2 | 16.47 | 4.30 | 0.039 | 3.89 |
Within Groups | 46.00 | 12 | 3.83 | |||
Total | 78.93 | 14 |
Research question: Does quantity of sleep impact problem solving ability?
H0: μ1 = μ2 = μ3, There is no difference in time taken to solve puzzle after sleeping for 5 hours, 7 hours or 9 hours
H1: At least one μi is different, There is a difference in time taken to solve puzzle after sleeping for 5 hours, 7 hours or 9 hours.
p-value = 0.039
Level of significance = 0.05
Since p-value is lessthan 0.05, we reject the null hypothesis and conclude that at least one μi is different.
So, there is a difference in time taken to solve puzzle after sleeping for 5 hours, 7 hours or 9 hours. Hence, quantity of sleep impacts problem solving ability.