Some graduate students seem to be overly optimistic. Several years of training in a graduate program does not guarantee a doctoral degree. It is important to work independently and be aware that there is always more work than you expect.

You can lead a horse to water but you can’t make it drink. Similarly, your supervisor can only present you with resources (knowledge, skills, direction), but they cannot make you digest them. Because there are so many things to learn, it takes a considerable amount of time to digest them all. Now, the question is, “How many hours should graduate students spend on their studies to obtain a doctoral degree?”

To answer this question, we first create a data frame. We assume that full-time students, hard-working full-time students spend 35 hours and 50 hours per week on their studies. We also assume that hobby learners spend 10 hours per week.

dat = data.frame(Year =  rep(c(1, 2, 3, 4, 5, 6, 7, 8), each = 52), Weeks = 1:(8*52))
dat$Hours_FullTime = 35 # where students are expected to study for 7 hours every day and take a good rest on weekends. Note that Article 32 of the Labor Standards Act stipulates that working hours are limited to 40 hours per week and 8 hours per day.
dat$Hours_HardworkingFullTime = 50
dat$Hours_Hobby = 10
head(dat)
##   Year Weeks Hours_FullTime Hours_HardworkingFullTime Hours_Hobby
## 1    1     1             35                        50          10
## 2    1     2             35                        50          10
## 3    1     3             35                        50          10
## 4    1     4             35                        50          10
## 5    1     5             35                        50          10
## 6    1     6             35                        50          10

We then calculate the cumulative sum of study hours for the different groups of learners.

dat$Hours_FullTime_Sum = cumsum(dat$Hours_FullTime)
dat$Hours_Hobby_Sum = cumsum(dat$Hours_Hobby)
dat$Hours_HardworkingFullTime_Sum = cumsum(dat$Hours_HardworkingFullTime)
head(dat)
##   Year Weeks Hours_FullTime Hours_HardworkingFullTime Hours_Hobby
## 1    1     1             35                        50          10
## 2    1     2             35                        50          10
## 3    1     3             35                        50          10
## 4    1     4             35                        50          10
## 5    1     5             35                        50          10
## 6    1     6             35                        50          10
##   Hours_FullTime_Sum Hours_Hobby_Sum Hours_HardworkingFullTime_Sum
## 1                 35              10                            50
## 2                 70              20                           100
## 3                105              30                           150
## 4                140              40                           200
## 5                175              50                           250
## 6                210              60                           300

Finally, we visualize the cumulative sums for the three groups of leaners over time. We assume that 52 weeks make up 1 year. It is not crystal clear how many hours of study are required to obtain a doctoral degree, but I tentatively estimate that at least 6000 hours of study are required given that students have prerequisites (e.g., knowledge of statistics and experimental methods, etc.). It is clear that hobby learners cannot obtain a doctoral degree even after 8 years.

After 3.3 years of study (i.e. 172 weeks), students who study 35 hours per week will have studied a total of over 6000 hours.

dat[dat$Weeks == 172,]$Hours_FullTime_Sum
## [1] 6020

After four years of study (i.e. 208 weeks), hard-working students who study 50 hours per week will have studied a total of over 10000 hours.

dat[dat$Weeks == 208,]$Hours_HardworkingFullTime_Sum
## [1] 10400