**2. Informally structured domains**

## **2.1. Tacit knowledge**

neophytes. This knowledge belongs to domain specialists, any person possessing application domain knowledge and/or having a role in the domain. Therefore, requirements engineers must elicit the application domain knowledge from domain specialists in order to include it into a set of solution requirements. It is a complex and highly creative activity that involves intensive cognitive activities, especially when the application domain has a high degree of informality where knowledge is informally stated, partially complete, implicitly assumed,

This phenomenon is presented in many disciplines such as *intelligent tailored solutions for illstructured domains, software for complex domains, intelligent tutoring systems, knowledge based systems, industrial design, among others*. In general, every necessity that requires a complex, highly creative solution, in which the requirements engineers are not a part of the application domain and need eliciting sufficient high-quality knowledge to understand the clients' need and expectations, faces this challenge [2]. Therefore, instead of focusing on the challenges of developing a requirements elicitation proposal for each of these complex areas, we have expanded the vision and generalized these domains as *informally structured domains* (ISD) [3],

In addition, solutions in ISD usually respond to clients and users' specific needs. As a result, they are diverse, consensus and unverifiable, and there are not fully defined processes to develop them. Therefore, these solutions or products must be developed according to the experience of domain specialists. These characteristics hamper the requirements elicitation process because the implications of knowledge transfer and transformation, the appropriate management of tacit knowledge and the issues of knowledge exchange must

In this context, we assume that a perspective of requirements elicitation that emphasizes the importance of knowledge management (KM) is a useful approach for addressing ISD inherent problems. KM is a discipline with the aim of enhancing an organization by sharing and managing knowledge flow among the people, taking advantage of information technologies [4]. Regarding KM in requirements elicitation is not new, but only few efforts offer a full

The knowledge management strategy for requirements engineering (KMoS-RE©) [6] is a highlevel plan oriented to the transfer or transformation of knowledge. The strategy has the aim of eliciting, structuring and creating knowledge that can be incorporated into a specification closest to the needs and expectations of clients. It is especially design from a full KM perspective in order to be applied in the context of ISD. The goal of this chapter is to describe the challenges of ISD and make a critical analysis of the KMoS-RE© strategy as a serious requirements elicitation proposal to face them. The analysis is based on the experience of applying the strategy in several ISD real cases. According the valuable results, the KMoS-RE© strategy promises to be a useful tool in the requirements elicitation of solution or products, especially

The remainder of this chapter is organized as follows: Section 2 presents a characterization of ISD in order to explain the challenges of eliciting requirements in these domains. This section also includes a wide explanation of tacit knowledge. Section 3 describes fundamental concepts of KM

tacit and unstructured [2].

86 Knowledge Management Strategies and Applications

be considered.

which is widely explained in Section 2.

knowledge management perspective [5].

in disciplines that share ISD characteristics [8].

As discussed above, a key element in a successful requirements elicitation process in ISD is *knowledge*. But, *what is knowledge?* Despite the widely recognised importance of knowledge as the main asset in today's society, defining it is an unresolved issue. In order to establish a baseline, this work supports the idea that knowledge has a subjective and personal quality. This view is based on the traditional definition of knowledge as *justified true belief*. However, as in Ref. [9], the focus is on the *justified* rather than the *true* aspect of belief. The *justified* view of knowledge makes it as dynamic, context-specific, humanistic, deeply rooted in individuals' value system and created in social interactions among individuals as opposed to the *true* view in which knowledge is absolute, static and non-human.

According to Ryle, knowledge can be classified in *knowing-that* and *knowing-how. Knowingthat* means storing and recalling facts. *Knowing-how* is a practical knowledge. This distinction carries through Polanyi's theory of personal knowledge, which classifies knowledge in *explicit* and *tacit* [10]. *Explicit knowledge* is transmitted through any language or formal representation: from text written in natural language to complex formalism as ontologies. On the other hand, *tacit knowledge* is personal and context-specific, generated by experience and therefore difficult to communicate and formalize.

Polanyi was interested in '… to show that complete objectivity, as usually attributed to the exact science, is a delusion and is in fact a false idea'. Thus, he examined how individuals gain and share knowledge. He concluded that knowledge is highly personal and questioned the commonly held view of the dispassionate objective scientist. He also emphasized that people can often know how to do things without either consciously knowing, or being able to articulate to others why what they do works.

According to Polanyi, *tacitness* is something personal, usually abilities or skills that people use to solve a problem or to do something valuable. *Tacitness* depends on people's experiences and learning. Polanyi suggested that all knowledge has a tacit component and discussed the process of how the tacit cooperates with the explicit. He also argued that language is a vital tool that people use to share knowledge, and that with the appropriate use of it, much, but not all, of this knowledge can be transmitted among individuals who share a mutually agreed language. When *tacitness* predominates, this articulation is not possible. However, it does not prevent knowledge from being transmitted by other means, such as observation or task repetition. This is what people do when learning to ride a bicycle or when an art master transfers knowledge to his or her apprentices. We should keep in mind that Polanyi's theory was generated in the field of psychology and his work was addressed towards perception. Thus, from Polanyi's perspective, any attempt to convert tacit knowledge to explicit will be unfruitful because it cannot be articulated at all.

Grant [11] provides a graphical representation of knowledge degradation as it is expressed by Polanyi's work (**Figure 1**). The bar represents how the knowledge is flowing in a continuum between tacit and explicit. The continuum ranges from knowledge inherently tacit to knowledge that can be easily expressed by words. The knowledge that can be expressed by words ranges from explicit to experts to explicit to most people. The knowledge explicit to experts requires specialized language. Most of this knowledge is also implicit, i.e. knowledge that can be expressed by words, but that for some reason it has not made explicit. The tacit knowledge ranges from ineffable to highly personal. Much of this knowledge is related to the use of instruments, such as playing piano or using a specialized machine.

To Gourlay [12], Polanyi's work has been misunderstood. He argued that some tacit knowledge does become amenable to analysis and decomposition, allowing recording it in an explicit form. Likewise, tacit knowledge in requirements elicitation has been misused. For example, Janik [12] has identified that the concept of tacit knowledge is used in two ways:


What is really important in requirements elicitation is making the most possible quantity of knowledge explicit. Whether it is tacit, implicit or that for some reason remains hidden, even because nobody asks.

**Figure 1.** Granularity of knowledge.

The problem of tacit knowledge in requirements elicitation is not new. Goguen [13] did an extensive analysis of the term from a social perspective. He analysed several methods to elicit requirements such as introspection, questionnaires, interviews, focus group and even protocol analysis. He argued that these methods have limitations to manage tacit knowledge. To Goguen, it is indispensable considering a social perspective to attend this problem; thus, he suggests using combinations of these methods besides including discourse, conversations and interactions analysis.

Later, Nuseibeh [14] emphasized the importance of tacit knowledge and how it may affect the requirements of elicitation process. For him, the responses of the domain specialists to direct questions about their domain of expertise do not reflect, neither their current behaviour nor the reality, for the large amounts of tacit knowledge that is handled by them. Thus, product developers or solution solvers should consider theoretical and practical techniques of *cognitive psychology, anthropology, sociology* and *linguistics* to have better results.

The importance of sharing tacit knowledge to improve the problem-solving processes or as a strategy to gain competitive advantage in organizations is undeniable. For example, Wyatt [15] argues that much of the medical progress in modern times has been attributed to an evolution from tacit to explicit knowledge. Despite that, nowadays, tacit knowledge remains as an ambiguous and inconsistent concept. We are aware that not all knowledge of specialists is susceptible to becoming explicit; however, it is essential trying this transformation with a well-founded strategy for the requirements as close as possible to the reality of the application domain.
