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ACTIVITY THEORY IN PRACTICE OF DESIGN AND DEVELOPMENT OF HUMAN-COMPUTER INTERFACES

Научная статья

Информатика, кибернетика и программирование

The paper is devoted to the design and development of “mass” and “professional” interfaces. The approach based on Activity Theory is considered. The example of the system with the interface based on Activity Theory approach is described.

Английский

2015-02-02

431 KB

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Vladimir Averbukh1,2, Nanalya Averbukh 3, Dmitriy Semenischev2

ACTIVITY THEORY IN PRACTICE OF DESIGN AND DEVELOPMENT OF HUMAN-COMPUTER INTERFACES

1IMM UrB RAS, 2Urals Federal University, 3Expert-Laboratory” LTD

Abstract

The paper is devoted to the design and development of “mass” and “professional” interfaces. The approach based on Activity Theory is considered. The example of the system with the interface based on Activity Theory approach is described.

Key word: Activity Theory, “Mass” interfaces, “Professional” interfaces

Introduction

The discipline of Human-Computer Interaction has been developed over the past fifty years since significant number of the computers work stably. Now a considerable part of all world programmers work in HCI domain. If in the first decade of HCI history the number of active users was near thousands now the possibility of human-computer interaction are available to some extent to almost all population of Earth.

At the same time, the situation of human-computer interaction and visualization is ambiguous. In some cases, the computerization of management processes leads to increasing of queues and problems in institution activities. Some of interfaces applied in mass services are inconvenient. They force people to spend considerable effort to learn and to use, and even lead to serious stress in some cases. The problems are related, in our opinion, the inadequate regard of what is traditionally related to human factors. Below, referring to the design of human-computer interaction and computer visualization we’ll mean design of “the human factor” elements for visual interactive systems.

The analysis based on the theory (or more exact theories) of human-computer interaction and computer visualization must develop to overcome the problems. And these theories are under developing. A lot of conferences devoted to visualization and HCI hold yearly. In many universities around the world special departments and research and educational institutes on Human-Computer Interaction and Computer Visualization have established. Note, however, that some practitioners do not know anything about the results of the research. Other practitioners expect from the theory only councils on design of the interface which is reduced to a choice of colors or placement of visual objects on the screen. Sometimes they said that there is no theory in human-computer interfaces and visualization, or that such theories are not necessary, in principle, because everything works fine without any theories.

On our opinion the theory is necessary, firstly, to analyze an existing state of the practice, secondly, to train new professionals and thirdly, (and this is the main) to use in the practical work. Without the theory there are no reliable methods of adopting and sharing really valuable experience, instead of the casual ideas which have appeared in connection with a certain level of hardware for interfaces and Computer Graphics and/or Software Engineering.

The analysis based on the theory (or more exact theories) of human-computer interaction and computer visualization must develop to overcome the problems. And these theories are under developing. A lot of conferences devoted to visualization and HCI hold yearly. In many universities around the world special departments and research and educational institutes on Human-Computer Interaction and Computer Visualization have established. Note, however, that some practitioners do not know anything about the results of the research. Other practitioners expect from the theory only councils on design of the interface which is reduced to a choice of colors or placement of visual objects on the screen. Sometimes they said that there is no theory in human-computer interfaces and visualization, or that such theories are not necessary, in principle, because everything works fine without any theories.

On our opinion the theory is necessary, firstly, to analyze an existing state of the practice, secondly, to train new professionals and thirdly, (and this is the main) to use in the practical work. Without the theory there are no reliable methods of adopting and sharing really valuable experience, instead of the casual ideas which have appeared in connection with a certain level of hardware for interfaces and Computer Graphics and/or Software Engineering.

The scientific theory should satisfy some requirements. Among them there are the discipline structurization, supporting of analytical functions in its frameworks, and the prediction of new phenomena. One may say about the explanatory and predictive force of the theory. Thus, on the basis of the satisfactory theory (at a given period of the discipline development) one may analyze and explain any known phenomena, predict the emergencies of new phenomena, concepts and facts, carry out a systematic description of the discipline as a whole. Thereby there is a possibility to fix available achievements, to transfer them in courses of study, to create conditions for the further development of the discipline. An important result of the satisfactory theories of HCI and Computer Visualization should be a scientific basis for the quality design, the development and the evaluation of HCI and visualization systems.

“Activity” approach to theory of human-computer interaction

Dealing with interfaces it is naturally to pay attention to psychological Activity theory developed in Soviet Union in the middle of the XX century. Activity theory is connected, first of all, with names of A. Leontev and S. Rubinshtein. Also we use the ideas of well-known Russian and Soviet physiologists A. Ukhtomsky, P. Anokhin, N. Bernstein.

The “activity” approach, actively developed since the late 80s, is one of the main approaches to the theory of human-computer interaction. The set of important papers on this subject was published beginning from the 80th and 90th years 9for example [1-4]). Just recently the monograph by Victor Kaptelinin and Bonnie A. Nardi was published [5].

When acquainting with Activity theory it seems that the theory was specially created in 30-s' year of the XX-th century for the future human-computer interactions so exactly its ideas are fit on the specifics of HCI. Activity theory can be supported by results of Psychophysiology theory developed about the same time. So this psychophysiologal “reinforcement” forms psychological and physiological basis of the theory of HCI. The Activity is considered as the conscious and purposeful process. The analysis of activity has to forego interface design. This analysis includes revealing of the activity purposes and ways of this purpose achievement, a determination of an understanding level for this purpose by a person and a definition of activity motives.

During the activity an action is realized, when the partial result, which it is reached, becomes a direct objective of the subject, and ceases to be realized when the target moved on and the former effect becomes only way to carry out other actions directed at a common goal. The action directed on the small purposes, is switched off from consciousness, passes in the subconscious.

One of the basic principles of activity theory is the hierarchical structure of activity. Activity theory differentiates between processes at various levels (or, rather, groups of levels), taking into consideration the objects to which these processes are oriented. Activities are oriented to motives, that is, the objects that are impelling by themselves. Each motive is an object, material or ideal, that satisfies a need. Actions are the processes functionally subordinated to activities; they are directed at specific conscious goals. According to activity theory, the dissociation between objects that motivate human activity and the goals to which this activity is immediately directed is of fundamental significance. Actions are realized through operations that are determined by the actual conditions of activity. (Cited by [1].) Thus, the hierarchy is established: activity – the realized actions – operations. The activity is divided into a set of conscious and motivated actions which, in turn, implemented a set of operations.

All activities of the system and its various changes one may present entirely in terms of results, which further emphasizes its critical role in the behavior of the system. This activity can be fully expressed in the questions, reflecting different stages of the system:

  1.  what the result should be obtained?
  2.  when the result should be obtained?
  3.  whereby (what mechanisms) the result should be obtained?
  4.  how the system verifies the adequacy of the obtained result?

Passivity of the dominant excitation, i.e. the dominant of the moment, can be considered as a source of passivity of perception and, consequently, a false perception. At the same time, this passivity provides stability of attention and a structurization of the received information. Activity to be effective and adequate, should always be corrected and be free all time of predefined schemas. However, the goals in the framework of an interface should not be achieved through a complex action, becoming an autonomous activity. The task of the designer is to minimize the complexity of the activity within the interface and to provide systemacity of interfaces. One may consider systemacity of interfaces as using similar actions to achieve the similar goals in different interface actions. Design of activity, actions and operations requires knowledges on the areas which can be attributed to Psychophysiology. Also it is important to take into account psychomotor factors of interface actions. Simplicity and ergonomics are especially important for mass interfaces.

The activity approach to designing human-computer interaction involves the analysis of the problem and description of action to tackle this problem. These activities consist of sets of conscious, motivated by goal achievement actions. In turn these actions are reduced to sets of operations. At each level of the hierarchy, a designer needs to reveal and to define clearly objectives, which are related to the implementation of activities. The design of operations needs to pay attention to the principles of systematicity. The development of mass and professional interfaces requires solutions of a number of additional problems.

Let's consider “instrumental” interfaces in connection with “Activity” approach.

One may understand instrumental professional interfaces as interfaces for practioners in the areas where a substantial part of the activities is interaction with people. That is, we consider the interfaces for various categories of clerks, health workers, salesmen, using them to perform their functions, as a tool their professional activities.

The mass instrumental type of interfaces includes “nonprofessional” general-purpose interfaces, using, for example, for tickets reservation systems, for health, banking, social and public services, etc.

“Recreational” interfaces (that is interfaces using in social networking nets, communicating services, games, and so on) are outside of our attention. Also we don’t consider interfaces for professionals dealing within information technologies. To a marked degree this limitation is connected with quality and usability criteria applied for these interfaces, such as time spent on the page, the number of “clicks” on some image, subjective evaluation of a small number of respondents, etc. These criteria are not suitable for “instrumental” interfaces. The quality criteria in this case should be based on evaluation of user activity results.

In the case of mass instrumental interfaces quality can be measured, taking into account the time spent by users to obtain the result and the level of stress during the result was reached. In this regard, laconic interfaces with the minimal requirements to user memory and attention are necessary. Hence we need to save and restore the current interface state and context. Interfaces that use the principles of the menu or any of the programming techniques are unsuitable here.

For professional instrumental interfaces the quality criterion may be measured through the number of people satisfied with the work of the institutions during some period of time. That is, we consider the number of customers, patients, clients, etc. who reached result satisfying them and not received serious stress. Thus, the level of stress of professionals, using the interface, are measured indirectly.

Stress may be measured both by interviews of interface users or visitors of the institution and by laboratory and “field” studies of their physiological indicators that reflect the level of stress. The size of time period depends on the term demanded for the decision of the given problems, for example, in any cases it is a working day, in any – a week, a month or even a year.

In case of “mass” interfaces the designer, formulating requirements to the interface, participates in formation of the future user activity. The user can't refuse to use the system because by using the interface she/he gets access to vital services, resources, information, etc. “Mass” interfaces have be intended to a “weak unit”. That is a person with minimal capacity to perceive and analyze information has to use this interface successfully.

In the case of “professional” interfaces the goal of user activity is predetermined beforehand. The problem under decision dictates the requirements for the interface generally. A “professional” also (as a user of “mass” interfaces) can't refuse to use the interface because her/his activity is strictly regulated.

The designer of the interface should study the goals and features of the given activity. She/he must not deform the activity and/or bring additional complexities to it. In our opinion it should be refused to use any intricate tuning in “professional” interfaces. Altogether it should avoid to use anything that may be considered as programing because programing is another activity supplementary to the main duties of a “professional”.

Within frameworks of the activity a “professional “ (that is a clerk, a health worker, a salesman) deals with a certain set of entities. For example, she/he handles personal documents, fills the form of internal documents, interacts with visitors, and sometimes takes the money and makes bills and receipts. Computerisation adds a new type of activity and creates a new entity - the human-computer interaction. One can watch examples of interfaces that continuously switch the clerk attention, prevent to interact with visitors, overloading her/him by additional tasks. It is necessary to analyze the activity generated by the “instrumental” interfaces from the standpoint of a possible “redundant” and “insufficient” level of computerization. In general it is necessary to reduce (instead of to increase) the number of entities that a “professional” has to process. That is why the designed interface should assume completely the functions of processing one or another entity. Then the interface will not be a new, additional and complicating entity in professional dealing.Designing “instrumental” interfaces is inseparable from generic issues in the institution where interfaces will be applied such as the correct organization of operations and document processing, data confidentiality and so on. These solutions tend to lie outside the competence of designers. But without them, all efforts can go down the drain.

An example. The system for health services

As an example we consider an idealized model of the computer system for health services.

Services are performed in the (poly)clinic by the staff of medical specialists. We suppose that the system includes a database of patients. The database (in the idealized case) contains information on all sickness cases of patient, treatment methods and objective data on her/his condition. The database is accessible in all healthcare settings (clinics and polyclinics) for all doctors in charge of the case.

It the framework of this model we realize two “instrumental” interfaces. The interface of a patient is considered as a mass “instrumental” interface and the interface of a doctor is considered as the professional “instrumental” interface.

The purpose of the patient activity is to get access to health services instead of dealing with the interface. The task of our interactive system is to direct the patient to the doctor quickly and easily.

After the identification the patient can choose a convenient time of a doctor appointment. In case of a repeated visit to the doctor the kept context of the previous (actual) sessions of the interface is used. Therefore storage and reproduction of the context is necessary. The laconic and simple interface should provide access to health services not burdening the patient additional tasks without the need for any programming. Interface helps the patient to achieve the goal of the activity directing her/him from one action to action. As a result the patient receives the coupon with information on a name of the doctor, number of an office and appointment time. The policlinic plan with the description of a potential route of movement for the patient is highlighted on the screen.

Access to the interface can be implemented as via the special terminal device standing in medical institutions, and via the Internet. By means of a specialist-registering clerk the file of subjective complaints of the patient may be filled.

The doctor interface includes actions on analysis of patient objective data, determining the diagnosis, an administration of a treatment and prescriptions. A doctor gains access to electronic medical records, including the data about treatment by other medical experts. Results of medical analyses, cardiograms, roentgenograms and other data received by means of various medical devices are accessible. The actual data is displayed without additional requests. The interface also includes a means of special documentation, that is filling of case history, writing data about administration of treatments and prescriptions. During this administration data about possible patient allergies and contra-indications. The number of steps required when using this interface is minimized.

It activity of the doctor in polyclinic, it is possible to reveal a set of entities he/she is dealing with. These entities are – patients, checkup devices, documents of various type which the doctor either analyzes, or fills. In frameworks of the interface under development all activity of the doctor on data analysis and documentation filling is completely computerized. This interface fully exhausts all function on documents dealing. Thus the new organization of activity of the doctor doesn't increase the amount of entities with which he/she deals.

The computerization of activity of the doctor assumes also usage of knowledge bases and expert systems. In some measure these possibilities are implemented during informing about patient allergies and contra-indications. Other advanced possibilities of knowledge bases and expert systems preferably have to be realized in other interfaces.

Conclusion

On the basis of Activity Theory one may costuct theoretical foundations of ergonomics for interfaces and visualization design. In conclusion, we emphasize that the theory is not needed for the theory, but we need the theory as a basis for designing proper human-computer interaction and visualization. . Our ideal is to develop personalized computer systems that are configured for a specific user, considering features of her/his perception and thinking.

References

1. Kaptelinin, V. Activity Theory: Implications for human-computer interaction. In B. Nardi, (ed), Context and Consciousness: Activity theory and human-computer interaction. Cambridge, MA: MIT Press. 1996, p. 107 – 110.

2. Kaptelinin V. Activity Theory // Encyclopedia of Human-Computer Interaction. Chapter 16. http://www.interaction-design.org/encyclopedia/activity_theory.html

3. Nardi, B. Activity Theory and Human-Computer Interaction In B. Nardi, (ed), Context and Consciousness: Activity theory and human-computer interaction. Cambridge, MA: MIT Press. 1996, p. 7-16.

4. Rogers, Y. New Theoretical approaches for Human-Computer Interaction. Annual Review of Information, Science and Technology, 38, 2004. Pp. 87-143.

5. Kaptelinin, V., Nardi, B. Activity Theory in HCI: Fundamentals and Reflections. Synthesis Lectures on Human-Centered Informatics. Morgan & Claypool. 2012.

 

Examples of “doctor” interface (prototype).


 

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