Bipolarity in Judgments and Assessments: Towards More Realistic and Implementable Human Centric Systems

We are concerned with the conceptualization, analysis and design of human centric systems. Such systems are meant, roughly speaking, as those in which a human being is a relevant (if not principal) element of a computer based system, and – by obvious reasons – there exists an inherent communication and articulation gap between the human and the computer implied first of all by different languages employed, i.e. strings of bits and natural language. Some human-computer interface (HCI) should therefore be employed to bridge that gap. Its very essence and purpose boils down to the use of most human consistent tools, techniques and solutions assuming that it is easier to change the machine than the adult human being. Obviously, there is a multitude of possible options in this respect and in our talk we consider one that is related to a proper representation and processing of human judgments and assessments that are crucial while considering any human – computer interaction. In this context we consider a known fact that when a human being is requested to provide a judgment or assessment concerning an option or course of action, he or she very often tends to to provide them in a bipolar version. This is meant in the talk in the sense of providing testimonies concerning separately positive and negative aspects (pros and cons), mandatory and optional conditions to be fulfilled, etc. To start with, we review two types of scales employed to quantified such type of bipolar testimonies. The first is the bipolar univariate scale, in which there is a neutral (0) point, and the negative part [0-1], related to a negative testimony, and a positive part [0,1], related to a positive testimony. The second is the unipolar bivariate scale in which two separate scales are employed, both with values in [0,1], expressing separately the positive and negative testimonies. The main problem is how to aggregate the positive and negative testimonies related to an option in question. We present two basic approaches, one that is decision theoretic and is based on some special multicriteria decision making scalarizing functions, and one which is logical and is based on multivalued logic with properly chosen definitions of logical operations. We present applications of these approaches to database querying and information retrieval, and to a multicriteria choice of design options of computer systems. We advocate such a bipolar setting and outline some possible future direction.