Sentence:  In a symposium and general exploration of the field of Person Perception and Interpersonal Behavior the discussion does not touch upon this aspect of the subject , with one <WSD>possible</WSD> exception ; Solomon Asch shows the transcultural stability of metaphors based on sensation ( hot , sweet , bitter , etc . ) dealing with personal qualities of human beings and events . 
Meaning of the word marked with <WSD> tags:  existing in possibility