We propose a model

Abstract. One of the primary goals in discovery science is to understand the human scientific reasoning processes. Despite sporadic success of automated discovery systems, few studies have systematically explored the socio-technical environments in which a discovery tool will ultimately be embedded. Modeling day-to-day activities of experienced scientists as they develop and verify hypotheses provides both a glimpse into the human cognitive processes surrounding discovery and a deeper understanding of the characteristics that are required for a discovery system to be successful. In this paper, we describe a study of experienced faculty in chemistry and chemical engineering as they engage in what Kuhn would call “normal ” science, focusing in particular on how these scientists characterize discovery, how they arrive at their research question, and the processes they use to transform an initial idea into a subsequent publication. We discuss gaps between current definitions used in discovery science, and examples of system design improvements that would better support the information environment and activities in normal science. Keywords: Socio-technical, information behaviors, knowledge discovery. 1.

: We provide two different model theoretic characterizations of a fragment of first-order logic which we call d-Horn formulas. This fragment is dual to the well known Horn fragment and has the same complexity for proving unsatisfiability. The method used in the characterization (syntactic translation functions between formulas which are mimicked by translation functions between models) might be applied to characterize other first-order restrictions. This paper is related to the work of Henschen and Wos (1974), but we study semantic translation together with syntactic renaming functions. We comment shortly on a number of applications of d-Horn formulas, one of which is the characterization of Context Free Grammars through a Horn [ d-Horn first-order theory. Keywords: Horn formulas, d-Horn formulas, renaming functions, model theoretic characterizations. 0.1 Introduction The Horn restriction of first-order logic (FO) is a relevant fragment, specially for Computer Science. For instance,...