For some months I study the discourse of attitude, and sometimes look back to the nice talk of Shilpa Arora and Mahesh Joshi. In the beginning of this work they consider a comment subjective if it cannot be objectively verified. Such definition seems to be quite reasonable if you are using some arbitrary judgement what can be objectively verified and what cannot. However, arbitrary judgement is subjective.
There is a long tradition in opinion mining to make some arbitrary classifications of the words or expressions. For example, many researchers consider opinions as subjective, and the statements about facts as objective. Many use external standard dictionary to classify expressions as positive or negative, WordNet to identify semantic similarity etc. It’s no wonder that so many studies suffer problems of identifying ironic expressions, sarcasm etc.
In my studies on expressing attitudes the discourse is taken as is, without arbitrary classification. Instead, I examine in which contexts the expressions appear. And result (for Polish language) is different. In the rough picture expressions of attitude seem to fall into two categories: “at the point” statements, and private, even intimate statements. There is a sharp distinction between these two kinds of expressions, clearly visible in the matrices of context relatedness of the expressions.