How do I subset a data frame according to specific strings?

[scunha]

Let's say I have the following dataset where I asked people to tell me what their staff role was and they were able to select multiple questions.

How can I tell R to calculate the mean score for the string 'Teaching'?

> df = data.frame(Staff=c('Teaching','Research','Research,Teaching','Administration', 'Faculty Management', 'Administration, Faculty Management'), score=c('2','1','3','2','1', '2'), length=c(10, 20, 30, 5, 10, 6))
> View(df)
> df
                               Staff score length
1                           Teaching     2     10
2                           Research     1     20
3                  Research,Teaching     3     30
4                     Administration     2      5
5                 Faculty Management     1     10
6 Administration, Faculty Management     2      6

[FJCC]

Here is one method that uses str_detect() from the stringr package. Notice that I manually changed the score column from characters to numbers.

df = data.frame(Staff=c('Teaching','Research','Research,Teaching',
                        'Administration', 'Faculty Management', 
                        'Administration, Faculty Management'), 
                score=c(2,1,3,2,1, 2), 
                length=c(10, 20, 30, 5, 10, 6))
df
#>                                Staff score length
#> 1                           Teaching     2     10
#> 2                           Research     1     20
#> 3                  Research,Teaching     3     30
#> 4                     Administration     2      5
#> 5                 Faculty Management     1     10
#> 6 Administration, Faculty Management     2      6
library(tidyverse)
df |> filter(str_detect(Staff,"Teaching")) |> 
  summarize(Avg=mean(score))
#>   Avg
#> 1 2.5

^{Created on 2022-10-24 with reprex v2.0.2}

[scunha]

Thank you, this was really helpful!