#load the data
df.raw 

#A tibble: 9,000 × 7

id    ques  alt  modality identity appearance choice

<int> <int> <int> <fct>   <fct>     <fct>      <fct> 

1     1      1     text    teacher  human        0     

1     1      2     video    peer    machine      0     

1     1      3     text     peer    machine      1     

1     2      1     text   teacher   machine      0     

1     2      2     voice    peer    human        1     

1     2      3     text   teacher   human        1      

#8,990 more rows