You could interpret or discuss it as:
Personalities: Characters. Perspectives on a particular character, perspectives on that character's opinions, background, etc. Perhaps he/she is portrayed in a negative light by one person, but in a positive light by another.
Events: Literally, events. People see the same thing differently, which is why we have multiple witnesses on the same event, as arguably no witness is truly reliable. People are influenced to a degree by factors such as shock, emotions, personal agenda, the fallibility of memory and so on.
Situations: This can be more broad and be applied to almost anything. A character could be in a relationship - what does he/she do? What does the partner do? Do they view or treat the 'situation' differently? Why? A character could be a teacher reprimanding a student for bullying another - what kind of approach does he/she take, is it different from another teacher's, do other people approve or disapprove, and what factors motivate that teacher to take that approach?
I didn't do Caesar but let's just say in simple terms for Ted Hughes' poems:
Personalities: Depicts Plath in a negative light, portrays himself as helpless to do anything, casts himself as the victim and Plath as the perpetrator.
Events: In one of the poems, he discussed an event that occurred that directly paralleled and differed from the perspective that Plath gave in one of her other poems - motivated by personal agenda, as he basically passes the blame on to Plath. In another event, he portrays Plath's loss of temper as unreasonable and violent, and dismisses her - a clearly biased perspective.
Situations: Hughes implied that the relationship was doomed from the start, and that he was helpless in any given situation, instead saying that Plath was responsible for her own demise.