Package: dplyr

Function: mutate()

1. Create a new treatment variable

Review the data (d3)

# A tibble: 5 x 2
     id cert        
  <dbl> <chr>       
1    10 elem ed     
2    11 special ed  
3    12 elem ed     
4    13 special ed  
5    14 secondary ed

I have preassigned teachers to treatment in another database and I know which teachers are in the treatment condition of my study and which are in the control condition. The teachers in treatment are IDs 10, 12, and 13. I want to assign treatment teachers a 1 and control teachers a 0.

I will first create a vector of the IDs that will be assigned to treatment. I could also do this within the variable creation function but for clarity I am pulling out the IDs and assigning those to a vector called treat.

Next I can create my new variable int by using the dplyr::mutate() function.

Then to assign 1s to treatment teachers and 0s to control teachers I chose to use dplyr::case_when().

Now I can use my vector treat and say when an id is in my treat vector, assign it a value of 1, otherwise (which is denoted by the word TRUE) assign it a 0.

treat <- c(10, 12, 13)

d3 %>%
  mutate(int = case_when(
    id %in% treat ~ 1,
    TRUE ~ 0
  ))
# A tibble: 5 x 3
     id cert           int
  <dbl> <chr>        <dbl>
1    10 elem ed          1
2    11 special ed       0
3    12 elem ed          1
4    13 special ed       1
5    14 secondary ed     0

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