-personal experiences and different perceptions occur so asking about a stressor is the best way to collect data. However, individual differences are not considered when doing this.
Retrospective inferences
-PP are asked to think back over 12 moths ago so answers may be different from when they originally answered the questions.
-memory is not stable as can forget the experience and not remember it correctly.
Subjective
-Something may be more stressful to one person than another. e.g. someone may dislike giving blood but someone else may not mind it.
