LEARNING BY EXPANDING: TEN YEARS AFTER

Introduction to the German edition of Learning by Expanding, published in 1999 under the title Lernen durch Expansion (Marburg: BdWi-Verlag; translated by Falk Seeger); also in the Japanese edition, published in 1999 under the title Kakucho ni yoru Gakushu (Tokyo: Shin-yo-sha; translated by a group led by Katsuhiro Yamazumi).


Yrjö Engeström

AUTOBIOGRAPHICAL NOTE

Learning by Expanding was published in Helsinki in 1987. A few months later, I began to work as a visiting professor of communication at the University of California, San Diego. I was appointed to that job on a permanent basis in 1989. In San Diego, the Laboratory of Comparative Human Cognition, founded by Michael Cole, became the home base of my research. However, during these years, I have continued to lead a research group at the University of Helsinki, too. In 1995, I was appointed Academy Professor by the Academy of Finland, a position that allows me to conduct a research program in Finland until the year 2000. 

The moves between Finland and California have exerted considerable influence on my thinking and research. In California, I had to learn about multiculturalism and to appreciate ethnic, religious, and other differences between people. I also had to learn to ground my theoretical ideas in concrete cases and carefully documented ethnographic detail. I also learned to appreciate certain things in Finland. These include collaboration and joint authorship between equal colleagues - something not easy to achieve in American social sciences. Most importantly, I learned to appreciate the relative openness of Finnish workplaces for critical research and bold interventions. 

THREE GENERATIONS OF ACTIVITY THEORY

I suggest that we may distinguish between three theoretical generations in the evolution of cultural-historical activity theory. The first generation, centered around Vygotsky, created the idea of mediation. This idea was crystallized in Vygotsky's (1978, p. 40) famous triangular model of "a complex, mediated act" which is commonly expressed as the triad of subject, object, and mediating artifact.

The insertion of cultural artifacts into human actions was revolutionary in that the basic unit of analysis now overcame the split between the Cartesian individual and the untouchable societal structure. The individual could no longer be understood without his or her cultural means; and the society could no longer be understood without the agency of individuals who use and produce artifacts. This meant that objects ceased to be just raw material for the formation of the subject as they were for Piaget. Objects became cultural entities and the object-orientedness of action became the key to understanding human psyche.

The limitation of the first generation was that the unit of analysis remained individually focused. This was overcome by the second generation, largely inspired by Leont'ev's work. In his famous example of "primeval collective hunt" Leont'ev (1981, p. 210-213) showed how historically evolving division of labor has brought about the crucial differentiation between an individual action and a collective activity. However, Leont'ev never graphically expanded Vygotsky's original model into a model of a collective activity system. Such a modeling effort was made in Chapter 2 of the present book.

The concept of activity took the paradigm a major step forward in that it turned the focus on complex interrelations between the individual subject and his or her community. In Soviet Union, the societal activity systems studied concretely by activity theorists were largely limited to play and learning among children. Contradictions of activity remained an extremely touchy issue. Since the 1970s, the tradition was taken up and recontextualized by radical researchers in the west. New domains of activity, including work, were opened up for concrete research. A tremendous diversity of applications of activity theory began to emerge, as manifested in recent collections (e.g., Engelsted, Hedegaard, Karpatschof & Mortensen 1993; Engeström, Miettinen & Punamäki in press; Nardi 1996). The idea of internal contradictions as the driving force of change and development in activity systems, powerfully conceptualized by Il'enkov (1977; 1982), began to gain its due status as a guiding principle of empirical research.

Ever since Vygotsky's foundational work, the cultural-historical approach was very much a discourse of vertical development toward 'higher psychological functions'. Luria's (1976) cross-cultural research remained an isolated attempt. Michael Cole (1988; see also Griffin & Cole 1984) was one of the first to clearly point out the deep-seated insensitivity of the second generation activity theory toward cultural diversity. When activity theory went international, questions of diversity and dialogue between different traditions or perspectives became increasingly serious challenges. It is these challenges that the third generation of activity theory must deal with. 

The third generation of activity theory needs to develop conceptual tools to understand dialogue, multiple perspectives and voices, and networks of interacting activity systems. In this mode of research, the basic model is expanded to include minimally two interacting activity systems. This move toward networks of activities, while still in an embryonic form, is anticipated in the present book (see in particular Figures 2.7 and 2.11) 

DEVELOPMENTAL WORK RESEARCH AS AGENDA OF APPLICATION

The central ideas of this book may be condensed into the following five claims: (1) the object-oriented and artifact-mediated collective activity system is the prime unit of analysis in cultural-historical studies of human conduct; (2) historically evolving inner contradictions are the chief sources of movement and change in activity systems; (3) expansive learning is a historically new type of learning which emerges as practitioners struggle through developmental transformations in their activity systems, moving across collective zones of proximal development; (4) the dialectical method of ascending from the abstract to the concrete is a central tool for mastering cycles of expansive learning; and (5) an interventionist research methodology is needed which aims at pushing forward, mediating, recording and analyzing cycles of expansive learning in local activity systems. 

At the time this book was written, my colleagues and I had taken the first steps toward constructing developmental work research as a methodology for applying activity theory, specifically the theory of expansive learning, in the world of work, technology, and organizations. Since then, a good number of studies and dissertations applying this framework have appeared, though mainly in Finnish (for introductions to developmental work research, see Engeström, 1991c; 1993; 1996a; see also Engeström & Middleton, 1996 for a broader overview of the currently emerging new wave of contextualist studies of work). 

In the following sections, I will briefly discuss experiences of and challenges to the theory of expansive learning that we have encountered in our research in various workplaces during the ten years after this book was initially published. 

THE HORIZONTAL AND THE VERTICAL IN DEVELOPMENT

In a recent paper (Engeström, 1996b), I recommended the reconceptualization of development along three parallel lines: (1) instead of just benign achievement of mastery, development should be viewed as partially destructive rejection of the old; (2) instead of just individual transformation, development should be viewed as collective transformation; (3) instead of just vertical movement across levels, development should be viewed as horizontal movement across borders.

Points 1 and 2 are fairly adequately covered in Learning by Expanding. The third point, that of development as horizontal movement across borders, was only beginning to dawn on me in 1987. In particular, the section 'Historical types of activity and expansive transition' in Chapter 4 of the present book reflects the influence of vertical evolutionary thinking in which qualitatively different types of activity tend to resemble fixed stages in a normative evolutionary ladder.

Three years after Learning by Expanding was written, I explicated my standpoint as follows. 

"From the viewpoint of historicity, the key feature of expansive cycles is that they are definitely not predetermined courses of one-dimensional development. What is more advanced, 'which way is up', cannot be decided using externally given fixed yardsticks. Those decisions are made locally, within the expansive cycles themselves, under conditions of uncertainty and intensive search. Yet they are not arbitrary decisions. The internal contradictions of the given activity system in a given phase of its evolution can be more or less adequately identified, and any model for future which does not address and solve those contradictions will eventually turn out to be non-expansive. An activity system is by definition a multi-voiced formation. An expansive cycle is a re-orchestration of those voices, of the different viewpoints and approaches of the various participants. Historicity in this perspective means identifying the past cycles of the activity system. The re-orchestration of the multiple voices is dramatically facilitated when the different voices are seen against their historical background, as layers in a pool of complementary competencies within the activity system." (Engeström, 1991a, p. 14-15)

Carol Kramsch (1993) recently proposed the concept of 'contact zone' to describe important learning and development that takes place as people and ideas from different cultures meet, collide and merge. Kris Gutierrez and her co-authors (Gutierrez, Rymes & Larson, 1995) suggest the concept of 'third space' to account for similar events in classroom discourse where the seemingly self-sufficient worlds of the teacher and the students occasionally meet and interact to form new meanings that go beyond the evident limits of both. Notions of 'perspective' (e.g., Holland & Reeves, 1996) have entered the vocabulary of activity theory.

In developmental work research, networks of multiple activities are studied empirically (e.g., Saarelma, 1993; Miettinen, 1993). A discussion between activity theory and Bruno Latour's (e.g., 1993) actor-network theory has been initiated (Engeström & Escalante, 1996; Engeström, 1996c). The concept of boundary crossing is emerging as a tool within developmental work research (Engeström, Engeström & Kärkkäinen, 1995). 

The acknowledgment of the horizontal dimension calls attention to dialogue as discursive search for shared meanings in object-oriented activities. Jim Wertsch (1991) has done much to introduce Mikhail Bakhtin's (1981; 1986) ideas on dialogicality as a way to expand the Vygotskian framework. Ritva Engeström (1995) went a step further by showing the parallel between Bakhtin's ideas of social language, voice and speech genre and Leont'ev's concepts of activity, action and operation. One might say that activity theory, and developmental work research as its application, have undergone a dialogical turn in the 1990s, inspired by Bakhtin's work in particular. This move is anticipated toward the end of Chapter 4 in Learning by Expanding.

While I push for the recognition and theoretical understanding of the horizontal dimension, I still argue that there is an important vertical or hierarchical dimension to learning and human cognition more generally (Engeström, 1995). Accounts of learning and innovation that only operate with horizontal or 'flat' notions of cognition miss a crucially important resource in failing to explore the particular complementary potentials and limitations of the different levels of mediational means.

Arguments for the importance of this vertical dimension have sometimes been interpreted as falling back to deterministic models of developmental stages leading to a fixed end point. For example, Klaus Holzkamp interprets Bateson's (1972) levels of learning and my use of them in Learning by Expanding as follows: "development depicted as learning passage through a logically pre-constructed matrix of stages of learning." (Holzkamp, 1993, p. 238)

Does an argument for a vertical dimension of hierarchical levels automatically imply a fixed course of development? Holzkamp overlooks here the dialectics of universality and context-specificity in development. This very issue was discussed by Sylvia Scribner (1985) in her analysis of Vygotsky's uses of history.

But just as Vygotsky does not offer a 'progression of cultural stages,' he does not offer a stage like progression of higher forms of behavior. One reason, I believe, is that he does not represent higher systems as general modes of thought or as general structures of intelligence in a Piagetian sense. Vygotsky addressed the question of general processes of formation of particular functional systems, a project quite at variance from one aimed at delineating a particular sequence of general functional systems. (...) Vygotsky's comparisons are always made with respect to some particular system of sign-mediated behavior - memory, counting, writing. (...) each of these systems has its own course of development; all of them ('higher' or 'cultural' by definition) advance from rudimentary to more advanced forms. But there is no necessity in theory for all functional systems characterizing the behavior of an individual, or behaviors in a given social group, to be at the same level. (Scribner, 1985, p. 132; first italics added by Y. E.)

In the context of my own argument, the spirit of Scribner's point translates as follows. I maintain that levels of learning represent 'general processes of formation of particular functional systems.' As general processes or general mechanisms, they contain no fixed order of progression, nor a fixed end point. They are continuously present as resources for the formation of specific innovations and transformations in particular organizations. It is characteristic to the levels of learning that they appear in various combinations and that there is continuous interplay between the levels. In this sense, consider the levels as a kit of wrenches of successive sizes. The kit itself is pretty general - it may be used in a tremendous variety of specific tasks. But it is always put into use in a particular context and situation. There is definitely a hierarchy in the kit. Yet there is no inherent necessity that the wrenches must be used in a specific order.

This insistence on working with both dimensions, the horizontal and the vertical, or more generally, the spatial-social and the temporal-historical, is also of tremendous practical consequence. 

"It is surely appropriate to avoid rigid, one-dimensional sequences being imposed on social reality. But especially among Anglosaxon researchers adhering to the ideas of Vygotsky, the standard alternative seems to be to avoid history altogether. Differences in cognition across cultures, social groups and domains of practice are thus commonly explained without seriously analyzing the historical development that has led to those differences. The underlying relativistic notion says that we should not make value judgments concerning whose cognition is 'better' or 'more advanced' - that all kinds of thinking and practice are equally valuable. While this liberal stance may be a comfortable basis for academic discourse, it ignores the reality that in all domains of societal practice those very value judgments and decisions have to be made every day. People have to decide where they want to go, which ways is 'up'. If behavioral and social science wants to avoid that issue, it will be unable to work out useful, yet theoretically ambitious intellectual tools for practitioners making those crucial decisions." (Engeström, 1991a, p. 10)

MULTIPLE SCALES IN CYCLES OF EXPANSIVE LEARNING

The theory of expansive learning is based on the dialectics of ascending from the abstract to the concrete. This a method of grasping the essence of an object by tracing and reproducing theoretically the logic of its development, of its historical formation through the emergence and resolution of its inner contradictions. A new theoretical idea or concept is initially produced in the form of an abstract, simple explanatory relationship, a 'germ cell'. This initial abstraction is step-by-step enriched and transformed into a concrete system of multiple, constantly developing manifestations. In an expansive learning cycle, the initial simple idea is transformed into a complex object, into a new form of practice. At the same time, the cycle produces new theoretical concepts - theoretically grasped practice - concrete in systemic richness and multiplicity of manifestations. 

In this framework, abstract refers to partial, separated from the concrete whole. In empirical thinking based on comparisons and classifications, abstractions capture arbitrary, only formally interconnected properties. In dialectical-theoretical thinking, based on ascending from the abstract to the concrete, an abstraction captures the smallest and simplest, genetically primary unit of the whole functionally interconnected concrete system (see Il'enkov, 1977; Davydov, 1990; also Bakhurst, 1991; Falmagne, 1995).

The expansive cycle begins with individual subjects questioning the accepted practice, and it gradually expands into a collective movement or institution. The theory of expansive learning is related to Latour's actor-network theory in that both regard innovations as stepwise construction of new forms of collaborative practice, or technoeconomic networks (Latour, 1987; 1988; 1993; see also Engeström & Escalante, 1996).

Ascending from the abstract to the concrete is achieved through specific epistemic or learning actions. Together these actions form an expansive cycle or spiral. The process of expansive learning should be understood as construction and resolution of successively evolving contradictions in the activity system. 

The theory of expansive learning was initially applied to large-scale transformations in activity systems, often spanning over a period of several years (Engeström, 1991c; Engeström, 1994). In several recent studies (e.g., Engeström, 1995; Engeström, Engeström & Kärkkäinen, 1995; Engeström, Virkkunen, Helle, Pihlaja & Poikela, 1996; Buchwald, 1995; Kärkkäinen, 1996), different scales have been used. Instead of entire corporations, the focus of these studies is on smaller units or teams. Instead of large cycles that take years, the researchers are looking at small phases and cycles that take minutes and hours on the one hand, and intermediate cycles or trajectories that take weeks or moths, on the other hand. Can such miniature and intermediate cycles be considered expansive?

The answer is yes and no. A large-scale expansive cycle of organizational transformation always includes smaller cycles of innovative learning. However, the appearance of small-scale cycles of innovative learning does not in itself guarantee that there is an expansive cycle going on. Miniature and intermediate cycles of innovative learning should thus be regarded as potentially expansive. Smaller cycles may remain isolated events, and the overall cycle of organizational development may become stagnant, regressive, or even fall apart. The occurrence of a full-fledged expansive cycle is not common, and it typically requires long-term effort and deliberate interventions. With these reservations in mind, the expansive learning cycle and its embedded actions may be used as a framework for analyzing smaller-scale innovative learning processes. 

TOWARD UTOPIAN METHODOLOGY 

The theory of expansive learning implies a radical localism. The fundamental societal relations and contradictions of the given socio-economic formation - and thus potentials for qualitative change - are present in each and every local activity of that society. And vice versa, the mightiest, most impersonal societal structures can be seen as consisting of local activities, carried out by concrete human beings with the help of mediating artifacts, even if they may take place in high political offices and corporate board rooms instead of factory floors and street corners. In this sense, it might be useful to try and look at the society more as a multi-layered network of interconnected activity systems, and less as a pyramid of rigid structures dependent on a single center of power.

In the approach advocated here, research aims at developmental re-mediation of work activities. In other words, research makes visible and pushes forward the contradictions of the activity under scrutiny, challenging the actors to appropriate and use new conceptual tools to analyze and redesign their own practice (see Engeström, Virkkunen, Helle, Pihlaja & Poikela, 1996; Engeström, in press). 

This means that practitioners are invited to take part in analyzing the disturbances of their activity. Practitioners typically view series of videotaped or otherwise recorded disturbances together with the researchers. Practitioners are asked to perform essentially the same analysis, to appropriate and use the same conceptual tools as the researchers. In some cases, practitioners actually collect major parts of the data, for instance videotaping each other's work actions and their own interactions. This type of research design is schematically depicted in Figure 1.

Figure 1: General design of developmental work research (Engeström, 1991b, p. 80)

In Figure 1, 'intermediate conceptual tools' refer to relatively data-driven and context-sensitive concepts. Such intermediate concepts are typically created in the process of collecting and analyzing data, and in the process of designing solutions to the contradictions identified. 

The basic design of such interventions follows Vygotsky's method of dual stimulation (see van der Veer & Valsiner, 1991). The crucial idea here is that a task is never just the task the experimenter designed. It is always interpreted and reconstructed by the subject by means of his or her internalized 'psychological instruments' that cannot be strictly controlled from the outside. Rather than giving the child just a task, ignoring her interpretation and reconstruction of the task, and observing how she manages, Vygotsky and his colleagues typically gave the child also potentially useful mediating artifacts - tools or signs. With them, the nature of the task could be radically changed. The potential capabilities and emerging new psychological formations of the child might be revealed. 

Such interventions are not based on prescriptions but on an introduction and collaborative application of new tools - literally on re-mediation or re-instrumentation. This is more than opportunistic, casual and informal dialogue; the researcher has a substantive contribution and must often be very determined and systematic in offering that contribution. 

Previous Vygotskian theorizing and research has mainly focused on a single individual or a dyad of two subjects using a single, well-defined mediating tool or artifact. Language as mediator has required a more complex approach - but studies of semiotic mediation have commonly excluded material instruments and tools. In interventionist studies of expansive learning, the mediational setup is complex and multi-layered both semiotically and instrumentally, yet the crucial events are temporally and spatially constrained so as to allow the collection of comprehensive high-fidelity data by means of videotaping. Analysis of such data forces the researcher to adopt a new view of mediation: instead of single instruments, one has to analyze a whole interconnected instrumentality (see Grismshaw, 1981, for an earlier, more restrictively discursive notion of instrumentality).

The concept of instrumentality implies that the instruments form a system that includes multiple cognitive artifacts and semiotic means used for analysis and design, but also straightforward primary tools used in the daily practice and made visible for examination, reshaping and experimentation. In such a dense mediational setting, a set of interconnected new sociocognitive processes are called for - literally, a new mentality is to be generated. The very complexity of the setup means that the instrumentality is constantly evolving; old tools are modified and new tools are created. 

This type of design requires a bold experimental attitude rather than the attitude of a casual observer and facilitator. Bringing about and traversing collective zones of proximal development is experimentation with activity systems. When practitioners face a mirror depicting their own disturbances, they often experience them as personal failures or even crises. Powerful and unpredictable cognitive, emotional and social dissonances are triggered. 

The developmental interventionist needs to record, analyze and support these processes. The researcher needs to record and analyze also his or her own actions and interactions. Interventions themselves must become an object of rigorous study. 

Learning by Expanding is an agenda for utopian research in concrete human activities undergoing historical transformations. It is an ambitious research program both theoretically and practically. It is still only in its early stages. 

REFERENCES

Bakhtin, M. M. (1981). The dialogic imagination: Four essays by M. M. Bakhtin. Edited by M. 

Holquist. Austin: University of Texas Press.
Bakhtin, M. M. (1986). Speech genres and other late essays. Austin: University of Texas Press.

Bakhurst, D. (1991). Consciousness and revolution in Soviet philosophy: From the Bolsheviks 
to Evald Ilyenkov. Cambridge: Cambridge University Press. 

Bateson, G. (1972). Steps to an ecology of mind. New York: Ballantine Books.

Buchwald, C. (1995). New work in old institutions: Collaborative curriculum work of a teacher 
team. Unpublished dissertation. Department of Communication, University of California, San 
Diego.

Cole, M. (1988). Cross-cultural research in the sociohistorical tradition. Human Development, 31, 137-151.

Davydov, V. V. (1990). Types of generalization in instruction. Reston, VA: National Council of 
Teachers of Mathematics. 

Engelsted, N., Hedegaard, M., Karpatschof, B. & Mortensen, A. (Eds.) (1993). The societal subject. Aarhus: Aarhus University Press.

Engeström, R. (1995). Voice as communicative action. Mind, Culture, and Activity, 2, 192-
214.

Engeström, Y. (1991a). Activity theory and individual and social transformation. Multidisciplinary 
Newsletter for Activity Theory, No. 7/8, 14-15.

Engeström, Y. (1991b). Developmental work research: A paradigm in practice. The Quarterly 
Newsletter of the Laboratory of Comparative Human Cognition, 13, 79-80.

Engeström, Y. (1991c). Developmental work research: Reconstructing expertise through expansive learning. In M. I. Nurminen & G. R. S. Weir (Eds.), Human jobs and computer interfaces. Amsterdam: Elsevier Science Publishers.

Engeström, Y. (1993). Developmental studies of work as a testbench of activity theory: Analyzing 
the work of general practitioners. In S. Chaiklin & J. Lave (Eds.), Understanding practice: 
Perspectives on activity and context. Cambridge: Cambridge University Press.

Engeström, Y. (1994). The working health center project: Materializing zones of proximal 
development in a network of organizational learning. In T. Kauppinen & M. Lahtonen (Eds.) Action research in Finland. Helsinki: Ministry of Labour.

Engeström, Y. (1995). Innovative organizational learning in medical and legal settings. In L. 
M. W. Martin, K. Nelson & E. Tobach (Eds.), Sociocultural psychology: Theory and practice 
of doing and knowing. Cambridge: Cambridge University Press.

Engeström, Y. (1996a). Developmental work research as educational research: Looking ten years 
back and into the zone of proximal development. Nordisk Pedagogik/Journal of Nordic Educational Research, 16, 131-143.

Engeström, Y. (1996b). Development as breaking away and opening up: A challenge to Vygotsky 
and Piaget. Swiss Journal of Psychology, 55, 126-132.

Engeström, Y. (1996c). Interobjectivity, ideality, and dialectics. Mind, Culture and Activity, 3, 259-265.

Engeström, Y. (in press). Expansive visibilization of work: An activity-theoretical perspective. 
Computer Supported Cooperative Work.

Engeström, Y., Engeström, R. & Kärkkäinen, M. (1995). Polycontextuality and boundary crossing in expert cognition: Learning and problem solving in complex work activities. Learning and Instruction, 5, 319-336. 

Engeström, Y. & Escalante, V. (1996). Mundane tool or object of affection? The rise and fall of the Postal Buddy. In B. A. Nardi (Ed.), Context and consciousness: Activity theory and human-
computer interaction. Cambridge: The MIT Press.

Engeström, Y. & Middleton, D. (Eds.) (1993). Cognition and communication at work. Cambridge: Cambridge University Press.

Engeström, Y., Miettinen, R. & Punamäki, R-L. (Eds.) (in press). Perspectives on activity theory. 
Cambridge: Cambridge University Press.

Engeström, Y., Virkkunen, J., Helle, M., Pihlaja, J. & Poikela, R. (1996). Change laboratory as a 
tool for transforming work. Lifelong Learning in Europe 1(2), 10-17.

Falmagne, R. J. (1995). The abstract and the concrete. In L. M. W. Martin, K. Nelson & E. Tobach (Eds.), Sociocultural psychology: Theory and practice of doing and knowing. Cambridge: Cambridge University Press.

Griffin, P. & Cole. M. (1984). Current activity for the future: The zo-ped. In B. Rogoff & J. V. 
Wertsch (Eds.), Children's learning in the zone of proximal development. San Francisco: Jossey-
Bass.

Grimshaw, A. D. (1981). Language as social resource. Stanford: Stanford University Press.

Gutierrez, K., Rymes, B. & Larson, J. 1995: Script, counterscript, and underlife in the classroom - 
Brown, James versus Brown v. Board of Education. Harvard Educational Review, 65, 445-471.

Holland, D. & Reeves, J. R. (1996). Activity theory and the view from somewhere: Team 
perspectives on the intellectual work of programming. In B. A. Nardi (Ed.), Context and 
consciousness: Activity theory and human-computer interaction. Cambridge: The MIT Press.

Holzkamp, K. (1993). Lernen: Subjektwissenschaftliche Grundlegung. Frankfurt am Main: Campus.

Il'enkov, E. V. (1977). Dialectical logic: Essays in its history and theory. Moscow: Progress. 

Il'enkov, E. V. (1982). The dialectics of the abstract and the concrete in Marx's 'Capital'. Moscow: Progress. 

Kramsch, C. (1993). Context and culture in language teaching. Oxford: Oxford University Press.

Kärkkäinen, M. (1996). Comparative analysis of planning trajectories in Finnish and American 
teaching teams. Nordisk Pedagogik/Journal of Nordic Educational Research, 16, 167-190.

Latour, B. (1987). Science in action: How to follow scientists and engineers through society. 
Cambridge: Harvard University Press.

Latour, B. (1988). The Pasteurization of France. Cambridge: Harvard University Press.

Latour, B. (1993). Ethnography of a "high-tech" case: About Aramis. In P. Lemonnier (Ed.) 
Technological choices: Transformation in material cultures since the neolithic. London: Routledge. 

Leont'ev, A. N. (1981). Problems of the development of the mind. Moscow: Progress.

Luria, A. R. (1976). Cognitive development: Its cultural and social foundations. Cambridge: Harvard University Press. 

Miettinen, R. (1993). Methodological issues of studying innovation-related networks. 
VTT/Technical Research Center of Finland. Group of Technology Studies. Working Paper No. 4.

Nardi, B. (Ed.) (1996). Context and consciousness: Activity theory and human-computer interaction. Cambridge: The MIT Press.

Saarelma, O. (1993). Descriptions of subjective networks as a mediator of developmental dialogue. The Quarterly Newsletter of the Laboratory of Comparative Human Cognition, 15, 102-112. 

Scribner, S. (1985). Vygotsky's uses of history. In J. V. Wertsch (Ed.), Culture, communication, and cognition: Vygotskian perspectives. Cambridge: Cambridge University Press.

van der Veer, R. & Valsiner, J. (1991). Understanding Vygotsky: A quest for synthesis. Oxford: 
Blackwell.

Vygotsky, L. S. (1978). Mind in society: The development of higher psychological processes. 
Cambridge, MA: Harvard University Press.

Wertsch, J. V. (1991). Voices of the mind: A sociocultural approach to mediated action. 
Cambridge: Harvard University Press.