Introduction

This report gives an in depth analysis of sleep of college students by using the “SleepStudy” dataset from https://www.lock5stat.com/datapage3e.html. The dataset comprises 253 observations on 27 variables, providing valuable insights into the sleep habits, psychological well-being, and lifestyle choices of college students.

The central goal of this analysis is to answer several research questions by examining the provided dataset. This report investigates different facets of college students’ sleep habits, academic achievement, psychological health, and lifestyle choices. The findings of this analysis will offer meaningful insights into the determinants of students’ sleep and its associated consequences.

The following research questions will be addressed in this report:

- 1. Is there a significant difference in the average GPA between male and female college students?
- 2. Is there a significant difference in the average number of early classes between the first two class years and other class               years?
- 3. Do students who identify as "larks" have significantly better cognitive skills (cognition z-score) compared to "owls"?
- 4. Is there a significant difference in the average number of classes missed in a semester between students who had at least one            early class (EarlyClass=1) and those who didn't (EarlyClass=0)?
- 5. Is there a significant difference in the average happiness level between students with at least moderate depression and normal           depression status?
- 6. Is there a significant difference in average amount of sleep over all days in the week between students who reported having at           least one all-nighter(AllNighter=1) and those who didn't (AllNighter=0)?
- 7. Do students who abstain from alcohol use have significantly better stress scores than those who report heavy alcohol use?
- 8. Is there a significant difference in the average number of drinks per week between students of different genders?
- 9. Is there a significant difference in the average weekday bedtime between students with high and low stress (Stress=High vs.              Stress=Normal)?
- 10. Is there a significant difference in the average hours of sleep on weekends between first two year students and other students?

By addressing these questions, we aim to provide a comprehensive understanding of the sleep patterns and related factors among college students, ultimately contributing to the well-being and academic success of this population.

Data

The dataset used in this report is comprised of 253 observations on 27 variables as shown below. The data was obtained from a sample of students who did skills tests to measure cognitive function, completed a survey that asked many questions about attitudes and habits, and kept a sleep diary to record time and quality of sleep over a two week period.

##   Gender ClassYear LarkOwl NumEarlyClass EarlyClass  GPA ClassesMissed
## 1      0         4 Neither             0          0 3.60             0
## 2      0         4 Neither             2          1 3.24             0
## 3      0         4     Owl             0          0 2.97            12
## 4      0         1    Lark             5          1 3.76             0
## 5      0         4     Owl             0          0 3.20             4
## 6      1         4 Neither             0          0 3.50             0
##   CognitionZscore PoorSleepQuality DepressionScore AnxietyScore StressScore
## 1           -0.26                4               4            3           8
## 2            1.39                6               1            0           3
## 3            0.38               18              18           18           9
## 4            1.39                9               1            4           6
## 5            1.22                9               7           25          14
## 6           -0.04                6              14            8          28
##   DepressionStatus AnxietyStatus Stress DASScore Happiness AlcoholUse Drinks
## 1           normal        normal normal       15        28   Moderate     10
## 2           normal        normal normal        4        25   Moderate      6
## 3         moderate        severe normal       45        17      Light      3
## 4           normal        normal normal       11        32      Light      2
## 5           normal        severe normal       46        15   Moderate      4
## 6         moderate      moderate   high       50        22    Abstain      0
##   WeekdayBed WeekdayRise WeekdaySleep WeekendBed WeekendRise WeekendSleep
## 1      25.75        8.70         7.70      25.75        9.50         5.88
## 2      25.70        8.20         6.80      26.00       10.00         7.25
## 3      27.44        6.55         3.00      28.00       12.59        10.09
## 4      23.50        7.17         6.77      27.00        8.00         7.25
## 5      25.90        8.67         6.09      23.75        9.50         7.00
## 6      23.80        8.95         9.05      26.00       10.75         9.00
##   AverageSleep AllNighter
## 1         7.18          0
## 2         6.93          0
## 3         5.02          0
## 4         6.90          0
## 5         6.35          0
## 6         9.04          0

Analysis

We will explore the 10 questions in detail below.

Q1: Is there a significant difference in the average GPA between male and female college students?

## [1] 3.123725
## [1] 3.324901

There was not a huge diefferen between male and female students average GPA scores. The male average was 3.12 compared to the female average of 3.32.

Q2: Is there a significant difference in the average number of early classes between the first two class years and other class years?

## [1] 2.070423
## [1] 1.306306

The average was 2.07 early classes for first and second year students, and 1.30 for the rest of the students. When the average number of early classes is rounded to the nearest class, we see that there is a difference of 1 early class, which turns out to be a 50% decrease after students reach two years. The histogram showing the distribution for the number of early classes each student is taking is also depicted above.

Q3: Do students who identify as “larks” have significantly better cognitive skills (cognition z-score) compared to “owls”?

## [1] 0.0902439
## [1] -0.03836735

Student who identified as “larks” do indeed have higher cognitive skills compared to “owls.” The average “lark’s” score was 0.0902439 compared to an average of -0.03836735 for “owls.”

Q4: Is there a significant difference in the average number of classes missed in a semester between students who had at least one early class (EarlyClass=1) and those who didn’t (EarlyClass=0)?

## [1] 1.988095
## [1] 2.647059

The average number of missed classes for someone with at least one early class was 1.988095 and for someone without any early classes was 2.647059. This means that if we round to the nearest class, students without an early class skip class one more time per semester then those with early classes.

Q5: Is there a significant difference in the average happiness level between students with at least moderate depression and normal depression status?

## [1] 27.05742
## [1] 23.08824

The average happiness score for normal depression status was 27.05742, while it was 23.08824 for students with moderate depression status.

Q6: Is there a significant difference in average amount of sleep over all days in the week between students who reported having at least one all-nighter(AllNighter=1) and those who didn’t (AllNighter=0)?

## [1] 7.271176
## [1] 8.07379

The average sleep for students who pulled at least one allnighter was 7.271176 hours compared to 8.07379 hours for students with no allnighters. So about one hour mor sleep per night by those who never had to pull an allnighter.

Q7: Do students who abstain from alcohol use have significantly better stress scores than those who report heavy alcohol use?

## [1] 8.970588
## [1] 10.4375

Students who abstain from alcohol had an average stress score of 8.970588, compared to a score of 10.4375 for those who reported heavy alcohol usage. So about 15% less stress from those who abstain compared to heavy drinkers.

Q8: Is there a significant difference in the average number of drinks per week between students of different genders?

## [1] 7.539216
## [1] 4.238411

There is a significant difference between the amount of drinks per week from males vs females. The male average is 7.539216 and the female average is 4.238411. This means females drank almost 50% less then the males.

Q9: Is there a significant difference in the average weekday bedtime between students with high and low stress (Stress=High vs. Stress=Normal)?

## [1] 24.715
## [1] 24.88543

There is not a significant difference in weekday bedtimes for normal stress students compared to high stress students, and they were only about 10 minutes apart. The normal stress average was about 1:53 a.m. and for high stress it was about 1:43 a.m.

Q10: Is there a significant difference in the average hours of sleep on weekends between first two year students and other students?

## [1] 8.213592
## [1] 8.221892

There is no significant difference between first two year students and all other years when it comes to sleep on weekends. They both were with 0.01 hours of each other on average at 8.213592 hours and 8.221892 hours.

Summary

This analysis explored several aspects of college students’ experiences, revealing notable trends in academic performance, lifestyle choices, and well-being. Key findings indicate that female students exhibit a slightly higher average GPA compared to male students. First and second-year students tend to have a significantly higher average number of early morning classes compared to students in later years. Notably, students identifying as “larks” demonstrate better cognitive skills than “owls.” Interestingly, students with at least one early class report missing fewer classes per semester than those without early classes. Students with normal depression status report significantly higher happiness levels compared to those with at least moderate depression. In terms of sleep habits, students who reported having at least one all-nighter sleep significantly less on average compared to those who did not. Abstaining from alcohol use is associated with lower average stress scores compared to heavy alcohol use. A significant gender difference exists in alcohol consumption, with males reporting a considerably higher average number of drinks per week than females. Conversely, no significant difference was found in weekday bedtimes between students with high and normal stress levels, nor was there a significant difference in average weekend sleep hours between the first two class years and other class years.

The implications of these findings are significant for understanding factors influencing students’ academic success, mental health, and lifestyle behaviors. The link between early classes and class attendance, as well as the association between chronotype and cognitive skills, suggests potential areas for academic and support service interventions. The clear disparities in happiness levels based on depression status and stress levels based on alcohol consumption underscore the importance of addressing mental health and substance use on college campuses.

References

From Lock5Stat.com: Onyper, S., Thacher, P., Gilbert, J., Gradess, S., “Class Start Times, Sleep, and Academic Performance in College: A Path Analysis,” April 2012; 29(3): 318-335. Thanks to the authors for supplying the data

Appendix

# Q1 Code: 
# male <- sleep %>%
#   filter(Gender == 1)
# average_gpa_male <- mean(male$GPA)
# print(average_gpa_male)
# female <- sleep %>%
#   filter(Gender == 0)
# average_gpa_female <- mean(female$GPA)
# print(average_gpa_female)

# Q2 Code: 
# first_two_years <- sleep %>%
#   filter(ClassYear <= 2)
# average_early_classes_first_two <- mean(first_two_years$NumEarlyClass)
# hist(first_two_years$NumEarlyClass, main = "Histogram of Number of Early Classes For First Two Year Students", xlab = "Number of Early Classes", col = "turquoise")
# hist(more_then_two_years$NumEarlyClass, main = "Histogram of Number of Early Classes For Not First Two Year Students", xlab = "Number of Early Classes", col = "blue")
# more_then_two_years <- sleep %>%
#   filter(ClassYear > 2)
# average_early_classes_more_then_two <- mean(more_then_two_years$NumEarlyClass)
# print(average_early_classes_first_two)
# print(average_early_classes_more_then_two)

# Q3 Code: 
# larks <- sleep %>%
#   filter(LarkOwl == "Lark")
# larks_average_z_score <- mean(larks$CognitionZscore)
# print(larks_average_z_score)
# owls <- sleep %>%
#   filter(LarkOwl == "Owl")
# owls_average_z_score <- mean(owls$CognitionZscore)
# print(owls_average_z_score)

# Q4 Code: 
# have_early_class <- sleep %>%
#   filter(EarlyClass == 1)
# missed_class_with_early <- mean(have_early_class$ClassesMissed)
# print(missed_class_with_early)
# no_early_class <- sleep %>%
#   filter(EarlyClass == 0)
# missed_class_without_early <- mean(no_early_class$ClassesMissed)
# print(missed_class_without_early)

# Q5 Code: 
# normal_depression <- sleep %>%
#   filter(DepressionStatus == "normal")
# happiness_normal_depression <- mean(normal_depression$Happiness)
# print(happiness_normal_depression)
# moderate_depression <- sleep %>%
#   filter(DepressionStatus == "moderate")
# happiness_moderate_depression <- mean(moderate_depression$Happiness)
# print(happiness_moderate_depression)

# Q6 Code: 
# with_allnighter <- sleep %>%
#   filter(AllNighter == 1)
# average_sleep_with_allnighter <- mean(with_allnighter$AverageSleep)
# print(average_sleep_with_allnighter)
# without_allnighter <- sleep %>%
#   filter(AllNighter == 0)
# average_sleep_without_allnighter <- mean(without_allnighter$AverageSleep)
# print(average_sleep_without_allnighter)

# Q7 Code: 
# no_alcohol <- sleep %>%
#   filter(AlcoholUse == "Abstain")
# stress_without_alcohol <- mean(no_alcohol$StressScore)
# print(stress_without_alcohol)
# heavy_alcohol <- sleep %>%
#   filter(AlcoholUse == "Heavy")
# stress_with_heavy_alcohol <- mean(heavy_alcohol$StressScore)
# print(stress_with_heavy_alcohol)

# Q8 Code: 
# male_drinks <- mean(male$Drinks)
# print(male_drinks)
# female_drinks <- mean(female$Drinks)
# print(female_drinks)

# Q9 Code: 
# high_stress <- sleep %>%
#   filter(Stress == "high")
# weekday_bedtime_high_stress <- mean(high_stress$WeekdayBed)
# print(weekday_bedtime_high_stress)
# normal_stress <- sleep %>%
#   filter(Stress == "normal")
# weekday_bedtime_normal_stress <- mean(normal_stress$WeekdayBed)
# print(weekday_bedtime_normal_stress)

# Q10 Code: 
# first_two_years_sleep_weekends <- mean(first_two_years$WeekendSleep)
# print(first_two_years_sleep_weekends)
# more_then_two_years_sleep_weekends <- mean(more_then_two_years$WeekendSleep)
# print(more_then_two_years_sleep_weekends)