A principal investigator (or group leader) receives unfavorable reviews of a paper submitted by the research group. One of the reviewers said the data were inconsistent. The principal investigator asks the paper’s first author, a staff scientist, to review the data from the paper. The staff scientist searches the computer files of a previous postbac fellow, who was supervised mainly by the staff scientist, but cannot find some primary data for two key experiments. Who was responsible for this problem? 

1. The principal investigator. 
   Correct; the principal investigator is ultimately responsible for the integrity of all the data.
   
   
2. The staff scientist. 
   Correct; the staff scientist is responsible because they supervised the postbac fellow and should have instructed the fellow on good recordkeeping practices.
   
   
3. The postbaccalaureate fellow. 
   Correct; the postbac fellow is responsible because they collected the data.
   
   
4. A senior technician who taught methods to the others and was a co-author. 
   Correct; if one assumes that the technician provided the postbac with some guidance for recordkeeping for the project.
   
   
5. All of the above. 
   This is the best answer because all members of the research team are responsible for the integrity of data even though some are more responsible than others.