PPOL670 | Introduction to Data Science | Week 8

Exploring Inaugural Presidential Speeches
ANSWER KEY

Data

inaug_dat <- read_csv("inaug_speeches.csv") 
head(inaug_dat)

## # A tibble: 6 x 5
##      X1 Name       `Inaugural Address` Date        text                         
##   <dbl> <chr>      <chr>               <chr>       <chr>                        
## 1     4 George Wa… First Inaugural Ad… Thursday, … "Fellow-Citizens of the Sena…
## 2     5 George Wa… Second Inaugural A… Monday, Ma… "Fellow Citizens:  \xa0\xa0I…
## 3     6 John Adams Inaugural Address   Saturday, … "\xa0\xa0WHEN it was first p…
## 4     7 Thomas Je… First Inaugural Ad… Wednesday,… "Friends and Fellow-Citizens…
## 5     8 Thomas Je… Second Inaugural A… Monday, Ma… "\xa0\xa0PROCEEDING, fellow-…
## 6     9 James Mad… First Inaugural Ad… Saturday, … "\xa0\xa0UNWILLING to depart…

Clean the data.

dat <- 
  inaug_dat %>% 
  transmute(president = str_to_lower(Name) %>% str_replace_all(.," ","_"),
            address = case_when(
                str_detect(`Inaugural Address`,"First") ~ "first",
                str_detect(`Inaugural Address`,"Second") ~ "second",
                str_detect(`Inaugural Address`,"Third") ~ "third",
                str_detect(`Inaugural Address`,"Fourth") ~ "fourth",
                T ~ "first"),
            date = as.Date(Date,"%A, %B %d, %Y"),
            year = lubridate::year(date),
            length = str_count(text),
            text = text)

# Adjust for one problematic date
dat[dat$president=="bill_clinton" & dat$address=="second",]$date = as.Date("1997-01-20")
dat[dat$president=="bill_clinton" & dat$address=="second",]$year = 1997

head(dat)

## # A tibble: 6 x 6
##   president     address date        year length text                            
##   <chr>         <chr>   <date>     <dbl>  <int> <chr>                           
## 1 george_washi… first   1789-04-30  1789   8641 "Fellow-Citizens of the Senate …
## 2 george_washi… second  1793-03-04  1793    805 "Fellow Citizens:  \xa0\xa0I AM…
## 3 john_adams    first   1797-03-04  1797  13914 "\xa0\xa0WHEN it was first perc…
## 4 thomas_jeffe… first   1801-03-04  1801  10170 "Friends and Fellow-Citizens:  …
## 5 thomas_jeffe… second  1805-03-04  1805  12947 "\xa0\xa0PROCEEDING, fellow-cit…
## 6 james_madison first   1809-03-04  1809   7031 "\xa0\xa0UNWILLING to depart fr…

Questions

(1) Do speeches get longer over time?

Answer: Not really. Though the variation in speech length varies less after 1950.

dat %>% 
  ggplot(aes(year,length)) +
  geom_line() +
  geom_point() +
  geom_smooth(method="loess",se=F)