I've noticed responses that at face value seem to be in contradiction with each other.
For instance, here @peter-flom writes
Short answer: Cluster analysis is about grouping subjects (e.g. people). Factor analysis is about grouping variables.
Whereas, over here on p1 of this York University document it is written that
Cluster analysis is also used to group variables into homogeneous and distinct groups. This approach is used, for example, in revising a questionnaire on the basis of responses received to a draft of the questionnaire.
Are cluster analysis and factor analysis both appropriate for grouping variables and cases? If so, what would prompt me to choose one over another in a particular context? If not, why not?