Many knowledge constructs have so far been conceptualized. The high amount of knowledge types that are being discussed may indicate the range of functions of what we know. The types of knowledge describe what content knowledge is about, e.g., knowledge about conceptual space, and what function knowledge fulfills regarding a specific task. Additionally, different qualities of knowledge have been discussed. In this way, knowl- edge has been characterized, for instance, as being superficial or deep, com- partmentalized or coherent, and inert or applicable. It can be assumed that knowledge qualities help to distinguish expert from novice knowledge. Knowledge qualities may, therefore, provide an orientation on deficits of learners’ knowledge and guide instructional approaches towards reducing these deficits. In order to systematize the various perspectives upon knowl- edge, De Jong and Fergusson-Hessler (1996) introduced a matrix consider- ing both the type of knowledge and the quality of knowledge, with respect to learning tasks that involve problem-solving. This matrix of types and qualities of knowledge will be introduced in this section.
3.1.1 Types of knowledge
De Jong and Fergusson-Hessler (1996) assume the epistemic per- spective of knowledge-in-use, meaning that “task performance forms the basis for the identification of relevant aspects of knowledge” (p. 105). In this perspective, the function of the various types of knowledge for a prob- lem-solving task is emphasized. Thus, there may be some links between De Jong and Fergusson-Hessler’s (1996) types of knowledge for problem-
solving and Fischer’s et al. (2002) epistemic activities. De Jong and Fergu- sson-Hessler (1996) distinguish situational knowledge, conceptual knowl- edge, procedural knowledge, and strategic knowledge. In the following paragraphs these types of knowledge and their corresponding epistemic ac- tivity will be summed up briefly. With respect to strategic knowledge the parallels to scripts sensu Schank and Abelson (1977) will be discussed.
Situational knowledge
“Situational knowledge is knowledge about situations as they typi- cally appear in a particular domain” (De Jong & Fergusson-Hessler, 1996, p. 106). Corresponding to the construction of problem space, situational knowledge may indicate that learners have acquired a representation of the problem and are able to abstract problem features. Individuals who have acquired situational knowledge may therefore have understood characteris- tics and categories of a range of problems within a domain.
Conceptual knowledge
“Conceptual knowledge is static knowledge about facts, concepts, and principles that apply within a certain domain” (De Jong & Fergusson- Hessler, 1996, p. 107). It can be argued that the epistemic activity of the construction of conceptual space corresponds with conceptual knowledge- in-use. Thus, conceptual knowledge enables learners to describe and define concepts. Traditional classroom teaching has been criticized for focusing on the facilitation of conceptual knowledge at the expense of other knowledge types. Mandl, Gruber, and Renkl (1994a) claim, for instance, that learners are typically facilitated and accustomed to acquiring conceptual knowledge, but they are not supported and accustomed to acquiring other knowledge types.
Procedural knowledge
“Procedural knowledge contains actions or manipulations that are valid within a domain” (De Jong & Fergusson-Hessler, 1996, p. 107). Pro- cedural knowledge enables learners to analyze and solve problems. With respect to epistemic activities, the construction of relations between con- ceptual and problem space is comparable to procedural knowledge. In some approaches, aspects of what has been also known as ‘procedural knowledge’ have rather been understood as a quality of knowledge, which describes whether knowledge was applicable or inert.
Strategic knowledge
Strategic knowledge is knowledge about the sequence of solution
activities (De Jong & Fergusson-Hessler, 1996). Strategic knowledge en- ables learners to identify separate steps and their order towards a problem’s solution. Strategic knowledge may be implicit to a sequence of epistemic activities or emerge as a non-epistemic activity when collaborative learners coordinate group activities. ‘Script’ may be another term for strategic knowledge (Kollar, Fischer, & Hesse, in press; Schank & Abelson, 1977). This notion of ‘script’ differs from what is meant by externally induced co- operation scripts as an instructional approach. Externally induced coopera- tion scripts are scaffolds to structure learners’ interactions as an intended instructional support. In contrast, scripts as strategic knowledge describe cognitive structures, which may be called ‘internally represented.’ Kollar et al. (in press) link these script terms and refer to knowledge as distributed over an environment (cf. Salomon, 1993b). In this way, externally induced cooperation scripts are a kind of manifestation of strategic knowledge. This two-fold use of the term ‘script’ will be discussed further in section 4.3.
3.1.2 Qualities of knowledge
In addition to types of knowledge, De Jong and Fergusson-Hessler (1996) discuss several knowledge qualities, namely level of knowledge, structure of knowledge, automation of knowledge, modality of knowledge, and generality of knowledge. Some of these qualities have clearly been re- ferred to as good vs. poor knowledge. This normative approach towards knowledge quality may be functional for educational psychologists and fa- cilitators to set goals of pedagogical interventions. For instance, knowledge may be deep or superficial with regard to the level of knowledge. This evaluation of knowledge quality is based on differences between ‘good’ expert knowledge and ‘poor’ novice knowledge. Experts do not differ much from novices regarding superior memory or specific types of knowledge, but rather by superior knowledge qualities.
Level of knowledge
Knowledge is often described as deep or surface-level. A deep level of knowledge is characterized as the understanding of basic concepts, prin- ciples, or procedures and enables learners to take multiple perspectives about a problem (Snow, 1989). In contrast, surface-level knowledge is asso- ciated with reproduction and rote learning (Glaser, 1991). Surface and deep knowledge refer to the question of whether or not a learner recognizes sur- face features of a problem or has deep knowledge about problem features that are not apparent (Chi & Bassok, 1989; Dufresne, Gerace, Thibodeau Hardiman, & Mestre, 1992). In a first step experts recognize deep features of problems and identify the applicable principles, concepts, and proce- dures. Only as a second step, do experts concretely apply the procedures to solve a problem. Novices, in contrast, aim to identify surface features of a problem and compare them with a surface-level goal state. Often, novices will then immediately engage in concrete operations to reduce the distance between a problem’s initial state and goal state (Dufresne et al., 1992).
Structure of knowledge
Structure of knowledge has been argued to be the main difference between expert knowledge and novice knowledge (Larkin, McDermott, Simon, & Simon, 1980). Experts chunk information together into larger, more meaningful units to build a hierarchic knowledge structure, known as schemata or scripts (Chi, Feltovich, & Glaser, 1981; Dufresne et al., 1992; Schank & Abelson, 1977). Knowledge may be hierarchically structured in reference to the importance of individual knowledge components. A hierar- chic knowledge structure is suited best for retention, for quick and efficient search processes, and for accomodating new knowledge (Boshuizen & Schmidt, 1992; Reif & Heller, 1982). This chunking of information has been well researched with recall tasks, where subjects are shown nonsensi- cal problem-state configurations (e.g., when the pieces on a chess board are arranged in a random configuration). When it is not possible to chunk in- formation, recall performance of experts and novices is equally poor (Dufresne et al., 1992; Gruber, Renkl, & Schneider, 1994).
Automation of knowledge
Another difference between novices and experts is, that novices use their knowledge by conscious, stepwise processes. Novices often need to make their knowledge explicit. Experts, in contrast, are claimed to make use of their knowledge in a continuous, fluid, and automatic process (De Jong & Fergusson-Hessler, 1996). Expert knowledge is therefore often referred to as tacit or implicit knowledge. It has been argued that this quality of expert knowledge may be acquired through informal learning, i.e. accumulating experience or mentoring, typically outside of educational institutions (Gelman & Greeno, 1989).
Modality of knowledge
Based on Paivio’s (1986) dual coding hypothesis, De Jong and Fer- gusson-Hessler (1996) suggest that knowledge can be stored in long-term memory as a set of propositions or images. The dual coding hypothesis ar-
gues that knowledge is more easily remembered when it is represented in the mind in multiple codes. Words and pictures may facilitate dual coding, but not necessarily implying that words foster internal representation as a set of propositions and that pictures foster internal representation as images. For instance, concrete words are represented in both codes. The word “table” typically activates a specific set of propositions as well as an image of a table.
Generality of knowledge
Knowledge may be more or less transferable between tasks. For in- stance, heuristics may be more or less domain independent. There has been some research on facilitation of domain independent problem-solving strategies (e.g., Schoenfeld, 1985) but there is a growing number of studies which emphasize domain dependence of expert knowledge (cf. Gersten- maier & Mandl, 2001; Mandl, Gruber, & Renkl, 1991).