Poster Sessions: Abridged Proceedings, pp. 235–237, HCI International 2001, August 5–10, 2001, New Orleans, LA, USA. © Lawrence Erlbaum and Associates, Inc. All rights reserved.
Usability versus Actability: A Conceptual Comparative Analysis Pär J. Ågerfalk
Stefan Cronholm
Dept. of Informatics (ESA) Örebro University, SE-701 82 Örebro, Sweden
[email protected]
Dept. of Computer and Information Science Linköping University, SE-581 83 Linköping, Sweden
[email protected]
Abstract Actability has been proposed as an important information system quality ‘metric’ – a concept that builds on usability to take the social context of human-computer interaction into account. Our objective here has been explicitly to compare usability with actability, and in doing so we have identified both similarities and differences between the two concepts. Actability seems to be narrower in the sense that it focuses on the use of information technology specifically within the context of doing business. However, within that context, it applies a broader perspective on the meaning and purpose of using.
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Introduction
Actability has been proposed as an important information system (IS) quality ‘metric’ – a concept that goes beyond usability (Ågerfalk, 1999). Cronholm et al. (1999) present actability as a concept that builds on usability to take the social context of human-computer interaction into account. Our objective here is explicitly to compare actability with usability, since no such comparison has been reported so far. The comparison is based on the definition of actability by Goldkuhl and Ågerfalk (2000), and the definition of usability by the International Organization for Standardization (ISO) (ISO 9241-11, 1998). The comparison explores similarities and differences in order to identify how the concept of actability can contribute to systems development and usage. The outcome will be used in our future research by learning from the accumulated usability knowledge to strengthen the further conceptualization and operationalization of actability.
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Usability
There are many definitions of the concept of usability. One definition, which has been generally agreed on, is that of ISO: ‘the extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use’ (ISO 9241-11, 1998). By use of the term ‘a product’, ISO refers to both software and hardware. Such a product can be ‘used … to achieve specified goals’, i.e. to produce intended outcomes. A user is anyone who interacts with the product. By ‘specified users’, ISO implies that different users might have different needs and comprehend the product differently. The terms ‘effectiveness’ and ‘efficiency’ imply that the specified goals are to be achieved with accuracy and completeness, and with as little expenditure of resources as possible. Furthermore, the goals should be achieved with ‘satisfaction’, i.e. without discomfort and with positive attitudes towards the use of the product. The ‘specified context of use’ includes users, tasks, equipment, and the physical environment, where ‘task’ is defined as the ‘activities required to achieve a goal’ (ibid.).
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Actability
Actability has been defined as ‘an information system’s ability to perform actions, and to permit, promote and facilitate the performance of actions by users, both through the system and based on information from the system, in some business context’ (Goldkuhl and Ågerfalk, 2000). The statement that information systems have ‘ability to perform actions’ implies that they are agents performing actions on someone’s behalf. In this context, actions are thought of as speech acts (Searle, 1969) or communicative actions (Habermas, 1984), i.e. performances of social actions by use of language. Someone performs an action to effect a change in the business, which creates an action relationship between the speaker and one or several listeners. It is important to note that IS actions are always ultimately derived from predefined rules and that a human actor is always ultimately responsible for them.
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Poster Sessions: Abridged Proceedings, pp. 235–237, HCI International 2001, August 5–10, 2001, New Orleans, LA, USA. © Lawrence Erlbaum and Associates, Inc. All rights reserved.
The statement that information systems should ‘permit, promote and facilitate the performance of actions by users’ implies that an IS should not only be easy to use and explicit about actions that it is possible to perform but should also encourage users to benefit from acting through it. User actions could be performed ‘through the system’, i.e. a user performs actions with an IS as a vehicle for communication. However, ‘based on information from the system’ implies that an IS is used to create action possibilities. It is important to note that the term user refers both to interacting users and to actors who use the system without physical contact with it – for example, actors who have the system, or an interacting actor, perform actions on their behalf (Ågerfalk, 2001). Hence, a manager of a sales department who is responsible for the business actions of his employees is a user of a sales support system with which his employees perform actions interactively, even though he might never see the system himself. Even someone using a paper document created by the system as a basis for manual action is regarded as a user. The ‘degree’ of actability possessed by a certain IS is always related to a particular ‘business context’ in which the IS is used. The business context includes actors’ pre-existing knowledge and skills regarding both the IS and the business tasks performed. Therefore, actability is not a static property of an IS but depends on the social structures surrounding it.
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Usability versus Actability
From a usability perspective, the purpose of using an IS is to achieve specified goals. Actability, on the other hand, emphasizes the performance of actions. Since actions are supposed to lead to desired business effects, these two formulations appear to be similar. The problem with a focus on goals is that it might lead to a teleological and overly rationalistic view of human action, and thus of the performance of tasks. Actions are multifunctional. For example, an action might lead to several business effects and several actions might lead to the same or a similar effect. In addition, actions are performed to conform to social norms. (Cf. Goldkuhl and Ågerfalk, 2000.) When designing for such a social understanding, a focus on goals might lead to decreased user satisfaction, if satisfaction is understood in a broader sense, with respect to the users’ social lives. A related issue is the use of ‘specified’ throughout the definition of usability. The set of actions that it is possible to perform through an IS is always ultimately derived from predefined rules, which are regulated during systems development. This is not reflected in the definition of actability, though. Finding out new ways of using an existing system might be a good thing. Nonetheless, it is important that users know what consequences their ‘improvements’ have for the action relationships created. A special case of ‘specified’ in the definition of usability is the formulation ‘specified users’, which indicates that usability emphasizes user differences while actability assumes a typical user category. From this case, it is clear that usability is more strongly rooted in cognitive science than actability is. Even though actability builds on usability, the main focus of actability is not on cognitive aspects and user differences. Rather, actability tends to stress the importance of a balance between organizational and individual aspects of IS usage. In general, the connotations of ‘user’ are different with respect to usability and actability. The usability focus is primarily on humans who directly and physically interact with a computer system. In the context of actability, a user is basically anyone affected by the actions performed through or by the system (Ågerfalk, 2001). More specifically, three meta-roles of users can be identified: the performer who performs an action interactively, the communicator on whose commission the action is to be performed, and the interpreter towards whom the action is directed (ibid.). It seems that the usability phrase ‘effectiveness, efficiency and satisfaction’ and the actability phrase ‘permit, promote and facilitate’ reflect similar aims. If a system permits and facilitates actions, it is probably effective and efficient as well. If it promotes action, it can probably be used with satisfaction. Usability should be understood within a ‘specified context of use’ – which tends towards the view of ‘one user using one computer’. This narrow human-computer view excludes other users who benefit from the IS. This restriction has also been criticized by Schmidt and Bannon (1992). Their criticism is made from the perspective of CSCW, and Bannon (1991) claims that usability must widen the focus to ‘encompass groups of people and machines’. The actability concept of ‘business context’ suggests a specific context of use, which is a social context wherein people cooperate to do business by the use of information systems. The usability concept of ‘product’ might correspond to the actability concept of ‘IS’. However, actability seems to put more focus on the software component and less on ergonomic issues concerning the work environment in which users act. 236
Poster Sessions: Abridged Proceedings, pp. 235–237, HCI International 2001, August 5–10, 2001, New Orleans, LA, USA. © Lawrence Erlbaum and Associates, Inc. All rights reserved.
A general observation is that the usability definition reflects more concern with measurability and has more of an engineering flavour compared to the more qualitatively and socially oriented actability.
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Conclusion
In this paper, we have identified both similarities and differences between the concepts of usability, as defined by ISO (ISO 9241-11, 1998), and actability, as defined by Goldkuhl and Ågerfalk (2000). From our analysis, actability seems to be narrower in the sense that it focuses on the use of information technology specifically within the context of doing business. However, within that context, it applies a broader perspective on the meaning and purpose of using, even though user divergences should be more properly acknowledged. It seems that actability can be understood as a domain-specific concept of usability, applicable in the context of information systems as tools for business action and communication. The question of predefinition versus flexibility needs further elaboration, as does the distinction between ‘effectiveness, efficiency and satisfaction’ and ‘permit, promote and facilitate’. The latter could probably be performed along the lines of the analysis of different interpretations of usability by Welie et al. (1999). Another important research topic is the understanding of the relations between goals, tasks and social action in the context of human-computer interaction. Finally, the role of hardware components and work environment in relation to actability needs further elaboration. Another, complementary way of continuing this work would be to analyse how the ISO definition of usability has been adopted by different researchers and practitioners, and how these adoptions form different perspectives on usability, such as, for example, those proposed by Löwgren (1995): general theory, usability engineering, flexibility, sociality, and subjectivity. These could then be related to actability to gain a more balanced picture of the relation between actability and usability, and of the roles these concepts might play in practice.
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