5. Discussions
As described in Sections 3 and 4, the different types and categories of knowledge tend to coexist, except definitional knowledge. Knowledge representation can be performed using knowledge-type-aware concept mapping, wherein the types and categories of knowledge play a vital role. It is worth mentioning that when a concept map represents a piece of knowledge claim, it may incorporate other relevant contents, such as those relevant to knowledge provenance. At the same time, other non-knowledge contents (e.g., information to help users grasp the meaning of the concept map) may also be considered part of a concept map. To understand this issue in greater detail, a creative design process has been considered and represented by a concept map of a solid-fuel-based engine developed for Mars exploration (Shafirovich and Goldshleger, 1992; Shafirovich et al., 1993; Hatchuel and Weil, 2008; Ullah et al., 2012).
Figure 9 depicts seven interdependent concept maps, denoted by C1,…,C7, which collectively represent the conceptual design of the solid-fuel-based engine. For the sake of analysis, internal combustion (IC) engines are considered to be available in the market a priori. The same, however, is not true for solid-fuel-based engines. Consider the concept map (C1), which boils down to the proposition that operation of an IC engine requires a fuel and an oxidizer. This is the definition of an IC engine, and therefore, represents a piece of definitional (or analytic a priori) knowledge. The second concept map (C2) boils down to the proposition that the earth’s atmosphere supplies ample O2 (> 20%) and hydrocarbons, but hardly supplies any CO2 (< 0.05%). This is a piece of informal-induction-based knowledge. Experimental data regarding chemical analyses of substances found in the earth’s atmosphere form the knowledge provenance for this piece of knowledge. The third concept map (C3) boils down to the statement that an IC engine uses O2 as an oxidizer and hydrocarbons as fuel. This qualifies as informal-induction-based knowledge, and data regarding oxidizers and fuels used in existing IC engines form the provenance for this piece of knowledge. Concept map (C4) boils down to the statement that an ample supply of fuel and oxidizer is essential for an IC engine. This, too, qualifies as a piece of informal-induction-based knowledge for which data concerning the performance of existing IC engine constitutes knowledge provenance. Up to C4, the design process deals with existing IC engine. From C5 onwards, the focus is shifted to a new engine using Magnesium (Mg) as solid fuel. The fifth concept map (C5) boils down to the proposition that the engine for Mars exploration may require fuel and an oxidizer. This is an analytic-a-priori-based creative knowledge. Since there exists no knowledge provenance (data or theoretical analysis) available to support this proposition; it is neither true nor false at the time of its conception. The sixth concept map (C6) boils down to the statement that Mars’ atmosphere supplies ample Mg, CO2 (> 95%), hardly supplies any O2 (< 0.1%), and does not supply hydrocarbons. This is a piece of informal-induction-based knowledge, and experimental data obtained from chemical analyses of substances found within Mars’ atmosphere form the provenance for this knowledge. The last concept map (C7) boils down to the proposition that an engine for Mars exploration may use Mg as a fuel and CO2 as an oxidizer. This represents analytic-a-priori-based creative knowledge, since there exists no knowledge provenance (data or theoretical analysis) available to support this proposition at the time of its inception. Thus, it is neither true nor false. This piece of knowledge, in turn, leads the design process of solid-fuel-based engines for Mars’ exploration into the embodiment, parametric, and detailed design stages, respectively.