1.         Introduction

Habermas' Critical Theory (Habermas1972, 1986) is a wide-ranging philosophy that has been appealed to by researchers and practitioners to provide a framework

for understanding information systems development (ISD) (Lyytinen and Klein, 1985) and other related issues.  In the main, it has been applied to ‘high’ level issues,

such as ensuring good dialogue and user requirements analysis, guiding I.S. research, etc. and has not often been applied to ‘lower’ level issues of technical design

and engineering. This paper explores how Habermas’ Critical Social Theory can be used as an integrated approach in the process of KBS design and use.

1.1          Knowledge Based Systems

Knowledge based systems (KBS) are IS tools used to provide intelligent decision support in human situations such as purchasing shares or estimating construction 

costs. Emerging from artificial intelligence, the knowledge base (KB) is more declarative than procedural in structure (Brandon et al 1988) and hence able to 

encapsulate complex knowledge. In use, the KBS takes the user through an inference session, in which questions are put to the user, inferences made, results 

offered and explanations given. Explanations can arise from intelligible representation of the formal logic and technical computations used in generating such 

information. The question sequence is dynamically created during the session and the explanations can be context-sensitive. Because of this, KBS technology offers 

remarkably flexible ways to express knowledge, human-like processing thereof, ability to deal with uncertain, even contradictory information. The declarative nature 

of its knowledge means KBS can often fulfil multiple roles, such as the ELSIE system described below.

The life of a KBS involves both its construction and use, each of which affects the other. Construction influences KBS use by providing the features that either 

enable or constrain the user in a real-life task. Use influences construction as engineers try to understand the situation into which the KBS will be inserted and 

anticipate how the tasks of the user will change over time. Often, the way a KBS is actually used differs from what was intended. Predicting how the KBS will be 

used is not straightforward, but is stimulated by the arrival of the technological artefact in the social context of the user, hence iterative approaches to construction 

like Basden, Watson and Brandon's (1995) Client Centred have been devised.

1.2          The Benefits of KBS Technology

Here we are primarily concerned, not with KBS technology, but with KBS in use by human beings to support them in their work. KBS possess the ability to change 

human task profiles (Castell, et. al., 1992), and the potential benefits to the users depend on the roles the KBS fulfils. Basden(1983) gave an early list of roles he had 

found to be important in practical applications of KBS, each providing different benefits:

·               Consultancy:                           Advice and guidance

·               Checklist:                               Nothing Overlooked

·               Training:                                 Scenarios

·               Communication:                      Shared Understanding

·               Knowledge refinement:           Stimulates reflection

·               Knowledge Repository:          Stores information

·               Programmed system:              Automatic handling of declarative kg and uncertainty

·               Demonstration vehicle:            Demonstrate any of the above 

For each role, different features of the KBS become important.  For example a KBS designed for a consultancy role must possess full and accurate knowledge,

while one designed for a communication role requires powerful explanation and what-if facilities instead.

1.3                     The Need for Theoretical Justification

It is unclear how to decide what roles a KBS may fulfil, what kind of features are required in each role and the shape these features should take. Such lack of clarity 

can result in uncertainty and misdirected effort during the development process. The list of roles above arose from practice; however, these roles have never been 

theoretically justified or grounded in theory. This paper examines the possibility that Habermas' action types could provide such a theoretical underpinning and lead 

to fruitful discussion between developers and users concerning the design of KBS.  

To understand such roles requires treating KBS as a social, not technical, science. A body of research has developed which has underscored the social nature of 

knowledge and the social elements of power, subjective meaning, human interests and consensus and conflict in IS design (Hirschheim et al 1991). Such a 

contribution has been seminal, and from this research useful IS methods have emerged (multi-view, ANT, ETHICS and Critical Systems to name but a few). 

Central to many of these is the philosophy of Jürgen Habermas.

2.         Habermas' Critical Social theory

Habermas' philosophical approach is to explain the world as a whole with principles to be discovered in reason. His social theory is centred on communication and

seeks to clarify the conditions, means, contents, constraints and objectives of all socially organised human behaviour (Habermas 1984). Indeed, Lyytinen (1986) 

proposes that Habermas' action types exhaust all social action. If this is so, Habermas' action types cover all possible roles in which a KBS might be used and 

should provide the theoretical underpinning we seek to clarify and scope the roles of KBS.

2.1          Habermas' Typology of Communicative Action Types and its Correspondence with KBS

2.1.1       Purposive-rational and Cultural Acts

All action types have a success aspect, which is defined as the appearance in the world of a desired state (Habermas, 1984, pg 285). Habermas' use of the concept 

`action' is very broad, incorporating any form of symbolic expression (verbal behaviour and text) and interlinked behaviour sequences such as occur in markets, 

court action or warfare (Lyytinen 1986). Habermas first key distinction in action types is between that of Purposive-rational and Cultural. A purposive-rational 

act arises when an actor seeks to achieve success in an objectified world, whereas, cultural action occurs when actors seek understanding. Table 2 displays the 

different types of purposive-rational and cultural action types.

Purposive-rational

Cultural

Instrumental

Normatively Regulated

Strategic

Communicative

Discursive

Dramaturgical

Table 2. Habermas’ Typology of Action Types

2.1.2       Instrumental Action (IA)

Habermas defines IA as "actors... seek[ing] to reach their goals in an effective and most efficient fashion [by] employing predictions drawn from physical and 

behavioural models" (Habermas, 1985, pp.127-128). These models are constructed by objectifying the ‘world’’ (Ngwenyama and Lee, 1997) where everything is 

regarded as a controllable object (Lyytinen 1986). Success is thus dependant upon valid empirical knowledge and appropriate technical tools and theoretical 

models.

This action corresponds with Basden’s (1983) definition of a consultancy role KBS and the conventional usage of such systems in technical arenas. The KBS 

establishes the values of certain variables (or truth of certain propositions) by its processes of backward and forward chaining, and these values are used to provide 

the advice.

2.1.3       Strategic Action (SA)

The difference between IA and SA is that success in strategic action is dependent on other actors, each of which is oriented to his own success and behaves co-

operatively only to the degree that this fits to his egocentric calculus of utility (Habermas, 1984, pp 87-88). These acting subjects achieve their ends by following 

decision rules (Lyytinen, K & Klein, H. 1985) and by orientating to, and influencing the decisions of other actors. These actions can be either open (war) or covert 

(indoctrination) and a prerequisite for success is that the actors have an accurate set of facts and a correct picture of the relevant relationships (Habermas 1979 from 

Lyytinen 1986).

Conventionally, a KBS used to support SA will also fulfil a consultancy role because of the similar need to enhance the success of the user.However, because the 

human element of the knowledge domain is more important, a SA KBS is likely to handle more uncertainty, and explanation facilities are likely to be more important.

The budget module ELSIE KBS was initially designed for this role, to advise quantity surveyors on setting a budget for new office buildings (Brandon, Basden,

Hamilton and Stockley, 1988). The knowledge not only contained physical, spatial and numeric calculations, but also knowledge of human preferences about such things

as furnishings, fittings and finishes. Furthermore, users were able to explore the breakdown of results leading to the estimation of cost.

2.1.4       Normatively Regulated Action (NRA)

NRA starts the action types that are cultural. It includes the social world and the Social Group to which an actor belongs as a role- playing subject (Habermas 1984 pg 85). 

NRA is so termed because the social group establishes norms to define a common predictable social world to which actors may orient (Habermas 1984 pg 88)and success is 

oriented within these ‘constraints' (Lyytinen 1986). Members of any group can expect other actors to behave in accordance with and with reference to these norms (Habermas 

1984 pg 89), a simple example of which is drivers conforming to the highway-code (Lyytinen 1986).

A KBS used to support NRA will often fulfil what Basden (1983) called a checklist role, in which the emphasis is to ensure all the relevant norms and issues are considered.

Senior surveyors, who had no need of its consultancy expertise, employed the ELSIE KBS for this very reason because they were legally responsible for the advice they gave 

clients.

2.1.5       Communicative Action (CA)

CA focuses on [reaching] a common agreement and understanding of social norms, meaning and values, and on maintaining social relationships (Habermas 1979). 

The central concept in CA is interpretation that refers to negotiations between people that admit them to achieve a consensus (Lyytinen 1986). Habermas draws 

particular attention to validity claims, which are directed toward the truth of facts, the rightness of norms and the sincerity of the actor (Kunneman, 1986, p230), and 

in such action the actor is confronted with a system of worlds: the objective world assumed in teleological action and the inter-subjective social world assumed in 

normatively regulated action (Lyytinen 1986).

A KBS used to support CA will most likely be designed for Basden's (1983) communication role. Several users gain a shared understanding both when they use the 

KBS together, discussing each question as it arises, and also via powerful explanation facilities. By making clear the interrelationships in the domain of knowledge 

and 'activating' the knowledge in the KBS to show how it works in specific situations of interest, such facilities can clarify areas of disagreement, including contextual 

misunderstandings, and stimulate consensus.  Such effects overlap with discursive action.

It was found by Castell, et al (1992), that the ELSIE KBS engendered CA when surveyor and client used the KBS together, discussing each question or explanation as 

it arose, and clarifying the client's requirements. The INCA KBS (Hibberd and Basden, 1995), which compiles contracts for the construction industry, was designed 

specifically for CA, to facilitate shared understanding in the usually adversarial relationship between contractor and employer.

2.1.6       Discursive action (DvA)

Discursive action is an expression of the ‘concept of communicative rationality' and the ‘central experience of the unconstrained, unifying, consensus bringing force 

of argumentative speech' (Habermas 1984 pg 10). It is in discursive action that validity claims are challenged, enabling consensus about the situation at hand. Claims 

are accepted or contested in argumentation where the ‘force of the better argument' determines which claims are upheld via ‘inter-subjective conviction' (Habermas 

1984 pg 36). Such a negotiated consensus requires conditions free of threats in which all participants are able to question validity claims and all listen to reason 

(Habermas, 1985, pg 151).

A KBS used to support DvA is most likely to be designed for what Basden (1983) called a knowledge refinement role, where self reflection by the users is 

encouraged to recognise areas where it would be beneficial to change their knowledge.

One of the authors was involved with such a KBS in the early 1980's, used by managers of business sectors in a company to reflect on the various aspects of the 

quality of their sector. Holding overview knowledge about these aspects of business, the KBS would pose probing questions, then ask the user to express their 

beliefs and explore reasons for them. This system was so highly valued that it was made company secret and never reported in the literature.

2.1.7       Dramaturgical Action (DmA)

Goffman (1959) first used the term in his work, 'The Presentation of Self in Everyday Life' and it is used by Habermas to describe the way an actor wishes to 

express himself to an audience when putting himself on 'stage'. Habermas distinguishes between a subject capable of free-will expression and an observable object 

with such properties as extension, weight and colour, to demonstrate the dramaturgical action of human actors (Habermas 1994 pg 91). Encounter and performance 

are key concepts in which participants form a visible public for each other and perform for one another, hence, attributes of style, aesthetic expression and formal 

qualities play an important role (Habermas 1984 pg 90 and 92).

Habermas states that dramaturgical action can be of a strategic nature, where stylistic features are employed to project a certain impression to an audience treated 

as opponents rather than as a public (Habermas 1984 pg 90 and 93).

Though Basden (1983) distinguished the demonstration role from others, he long felt that this role required better underpinning. We can see a similarity between this role

and dramaturgical action, in that in both the presentation of something is of primary importance.

2.1.8       A defence for Dramaturgical Action as a feature of IS via the HCI

Lyytinen (1986) states that dramaturgical action is of marginal interest to information systems design. However, not only do we find Basden's demonstration role to be 

important, but also multimedia presentations often have a dramaturgical as well as communicative purpose. Even though a the user(s) are not interacting with a fellow 

human,a KBS, via the human-computer interface (HCI), presents the intentions and social colour projected onto and into it by its human shapers. With the array of 

presentational tools available to an engineer, the HCI can become quite dramatic and, strategically, the engineer need be aware of such a dynamic to maximise the 

usability of the system.

3.         Applying Habermas’ Action Types to KBS construction, use and development 

In this section we attempt to integrate Habermas' thinking into the process of expert systems design, construction and development. We discuss a number of 

features and characteristics of KBS, how their form and importance varies and how such features may be enhanced according to Habermas' social theory. The 

discussion is summarized in Table 2.

3.1          Function of KBS

Here we are concerned with the purpose of a KBS, i.e. why it is constructed and in what ways it supports the users. This is of importance in determining what 

knowledge is required for the system.

Habermas' classification describes action as either purposive-rational or cultural. If the KBS is of a cultural nature, normatively regulated, communicative and 

discursive features must be provided and dramaturgical issues considered. This not only impacts the nature of the knowledge required for the KBS, but the design, 

construction, usability, social involvement, human-computer interface and cost of the system. Such a decision will involve ethical convictions, financial commitments, 

time constraints and issues of control and power.

In functioning purposive-rationally, KBS are likely to be cheaper, easier and quicker to construct and the user(s) and engineer(s) are likely to have significant power 

over the outcome of the finished artefact.

3.2                     Life-world of user

The life-world is the linguistic and cultural framework within which actors communicate. Habermas calls it the 'reservoir of taken-for-granteds, of unshaken 

convictions that participants in communication draw upon in cooperative processes of interpretation' (Habermas 198 Volume II pg124-127).

The life-world is important in that it emphasises social ‘context’. Such contextual issues apply to the HCI, the way the knowledge is presented and the way 

questions are asked and explanations provided. This problem will be most evident in a KBS built for cultural action, where the inter-subjective world of values, 

norms, feelings and quality of life is reliant on such appreciations of life-world.

Table 2: Habermas, Action Types and KBS.