Michael Köhler, Roman Langer, Rolf von Lüde, Daniel Moldt, Heiko Rölke and Rüdiger Valk (2007)
Socionic Multi-Agent Systems Based on Reflexive Petri Nets and Theories of Social Self-Organisation
Journal of Artificial Societies and Social Simulation
vol. 10, no. 1
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This contribution summarises the core results of the transdisciplinary ASKO project, part of the German DFG's programme Sozionik, which combines sociologists' and computer scientists' skills in order to create improved theories and models of artificial societies.
Our research group has (a) formulated a social theory, which is able to explain fundamental mechanisms of self-organisation in both natural and artificial societies, (b) modelled this in a mathematical way using a visual formalism, and (c) developed a novel multi-agent system architecture which is conceptually coherent, recursively structured (hence non-eclectic) and based on our social theory.
The article presents an outline of both a sociological middle-range theory of social self-organisation in educational institutions, its formal, Petri net based model, including a simulation of one of its main mechanisms, and the multi-agent system architecture SONAR. It describes how the theory was created by a re-analysis of some grand social theories, by grounding it empirically, and finally how the theory was evaluated by modelling its concepts and statements.
Multi-Agents Systems, Petri Nets, Self-Organisation, Social Theories
Introduction: The ASKO Project
- One main aim of the socionic research programme is to construct multi-agent
systems (MAS), which adopt the robustness, flexibility, fault-tolerance, and
adaptivity of natural socialities. But what kind of entities constitute
and reproduce these attributes of social systems? This became the early core
question of our project Acting in social contexts (short:
ASKO) (University of Hamburg)
So we went a step back from simulating and executing models in favour
of taking a closer look at empirical and theoretical research on
natural ways of constituting and structuring stable but flexible
- With respect to other socionic projects, covering theoretical approaches like
systems theory, methodological individualism, or network theory, ASKO
developed an amending, discrete perspective. From social theories that
especially deal with the micro-macro link of sociality, it extracted more or
less implicit concepts of mechanisms that produce recursive processes and
structural dynamics and, in the end, emergent, flexible, and stable structural
orders. Those concepts were grounded by empirical research on
self-administration processes in universities, and then combined to a middle
range theory of social self-organisation (TSSO).
Our work aimed at building and modelling a theory capable of
describing extremely different self-organising processes and
- This theory then got modelled with Petri nets. Petri nets as a
high-level, visual and highly abstract formalism allow to
operationalise core mechanisms of social theories. The interrelations,
discrepancies, (in-)consistencies and gaps of the sociological theory
can be graphically shown and logically evaluated. By this means,
logical or conceptual gaps were minimised. The structural analysis of
these nets serves as the explication of possible and predictable
social dynamics and processes, and as an evaluation of the TSSO.
- Simuation methods are able to estimate the quality of
a model by comparing its prediction with the real world.
Nevertheless, simulation methods treat models as black boxes:
It is not possible to discriminate models describing the same
dynamics, i.e. having the same extension. As we aim to build
a theoretical model which contemporaneously will be an approach for
MAS architectures, our focus lies on the inner structures of the model
Structure of our Contribution
- Our research approach is a recursive process (cf.
Figure 1). It starts with the social theory. This
theory is modelled, the resulting Petri net model is evaluated, and
the results are used to improve the social theory. The revised theory
is modelled again and so on. The result of multiple
passages through this recursive process is a novel concept for
MAS-architectures allowing to change and rearrange the structure while
running. In this contribution we concentrate on
this process and will describe briefly its relationship to our
empirical research and to our multi-agent system SONAR.
- The paper is structured as follows: A short description of the
ASKO approach concerning socionic theory re-analysis
and modelling is given in Section 2. An overview of
the main results, namely the Petri net based model of the theory of
social self-organisation (TSSO) is given in Section 3.
Section 4 describes the relationship to our empirical research.
Section 5 presents the multi-agent system SONAR, designed
following the principles of the TSSO approach.
The last part will provide a summary and an outlook.
Socionic Theory Formation, Modelling, and Evaluation
- The development of the theory of social self-organisation roots in
different origins, in social theory formation, modelling, and
evaluation combined with empirical research and practical design
concerning MAS (cf. Figure 1).
Theory Formation: Systematic Combination of Theories,
Empiricism and Practical Problems
- The sociological approach of ASKO is a reaction on a specific
professional state. Sociology possesses a wide and fruitful variety of
theories and explanations and a colourful bunch of empirical
approaches. But whenever facing a new kind of explanation problem,
finding a suitable theory and combining it with empirical insights
becomes more and more demanding. Now, due to actual societal
tendencies, (even social) science will be obliged to switch into
"Mode 2 of knowledge production" (Gibbons). This means combining
theoretical models and empirical descriptions, while transcending
disciplinary borders, to focus explanation powers on dealing with
complex and opaque (even social) problems. Sociology needs an
amendment to its variety: a clear set of bounded theoretical models of
social mechanisms, and specific rules how to combine them and how to apply
them to the handling of practical problems. (Recently, this need for
combination became a main issue at least in the theory section of the
German Sociology Association, DGS.)
- ASKO used and developed a heuristic
approach to bridge inner disciplinary divides, notably between
different theories as well as between theory and empiricism (v. Lüde et al.
2003). This method is the well known methodology of heuristic
research (cf. Kleining 1994, 1995, 1999; Kleining and Witt 2001). It is capable
of dealing with any kind of data from complex theoretical texts to
simple empirical descriptions. And because it favours an analysis on
similarities, it draws attention to hidden connections. Now of course ASKO could not take every social
theory in this analysis on similarities, we had to select. We have
omitted theories used by the cooperating socionic projects (systems
theory, individualistic approaches, network theory). Chosen were
theories which (a) dispose over a comparable level of abstraction, (b)
are grounded in empirical research, (c) systematically deal with the
micro-macro-link, and (d) focus on constellations of actors or social
units with a specific balance point on inequalities, and on struggles
for distribution structures and forms of social order. The chosen
theories were the Habitus-Field, Capital, and Institutionalising
Theory of Pierre Bourdieu, the Power and Norm Formation Theory of
Heinrich Popitz and the Process and Figuration Theory of Norbert
Elias. Some theoretical models provided by Anthony Giddens and Zygmunt
Bauman were added. For the results of the reconstruction of these
theories see (v. Lüde et al. 2003); for a
detailed elucidation of the analysis process and how the theories got
integrated, see (Langer 2003, 2005a).
- The analysis on similarities between
those theories resulted in an outline of a general theory of social
self-organisation. This outline was additionally grounded on empirical
research on universities and schools. The combination of the
theoretical and empirical research resulted in a middle range theory
of basic informal and blind mechanisms of self-organisation
in educational institutions (TSSO) (Langer 2005a). This is of course still a
preliminary outline but already based on soundly empirical grounding
The Modelling Formalism: Petri Nets
- This pure sociological analysis was
accompanied by modelling the original theories and the outlined
integrative theory with Petri nets. A sociological integration was
carried out at the same time. We have chosen Petri nets as our
project formalism for several reasons. Details can be found in (Girault and Valk
- Petri nets can be represented in a graphical way, which is
beneficial for the interdisciplinary discourse with social
scientists (after a certain familiarisation phase).
- Petri nets are based on the fundamental duality of passive and
- Petri nets inherently express structural as well as process
concepts the same way ("processes of Petri nets are Petri nets
- Unlike other automata formalisms Petri nets allow the modelling of
(i.e. independent events). They also allow for an intuitive
representation of the notions of causality, alternatives,
parallelism, non-determinism, resource, action, and others.
- Well established extensions of the basic formalism exist, e.g. for the incorporation of structured data, object-orientation, timed
- A broad spectrum for the analysis of Petri net models exist,
e.g. structural analysis or model checking.
- Petri nets are chosen for the formalisation of UML models.
- Petri net models are directly executable, thus it is possible to gather
arbitrary simulation data form the models
- In the following we give an informal
description of Petri nets, for an introduction cf. (Kummer 2001). A Petri net is
a (bipartite) directed graph with two different kinds of nodes:
places (passive elements) and transitions (active
elements). Places represent resources that can be available or not, or
conditions that may be fulfilled. They are depicted in diagrams as
circles or ellipses. Transitions are denoted as rectangles or
squares. A transition that fires (or: occurs) removes
resources or conditions (for short: tokens) from places and inserts
them into other places. This is determined by arcs that are directed
from places to transitions and from transitions to places. Petri nets
are a well established means for the description of concurrent
systems. An example for the dynamics of Petri nets is given in Figure 2. The transition act may occur (fire),
because the places p1, p2, and p3
(the preconditions of the transition act) are marked, but it does not have to
fire. If the action is carried out, the marking of the net changes:
now the places p4 and p5 (the post-conditions)
will be marked.
A possible Action and the Outcome of the Action
- Coloured Petri nets (Reisig 1991; Jensen 1992) allow to combine parts of a
Petri net with the same structure by a folding operation.
Arcs are inscribed with variables that are bound to available
(coloured) tokens (e.g. integers, strings etc.). So one transition may
describe a multitude of possible actions dependent on its binding -
each of these bindings is equivalent to a single transition in the
unfolded ordinary (non-coloured) Petri net. One transition of the
coloured net usually stands for a multitude of transitions of an
uncoloured net. Coloured tokens are removed and created in accordance
to the binding of the firing transition.
- The paradigm of nets-within-nets
introduced by R. Valk in (Valk
formalises the aspect that tokens of a Petri net can also be nets (see
Figure 3). Such net tokens
are a conceptual advancement (from simple Petri nets to coloured Petri
nets to nets-within-nets), because they introduce recursivity to the
Petri net theory (Köhler and Rölke 2004).
Taking this as a view point it is possible to model hierarchical or
recursive structures in an elegant way. Note, that this feature is
essential to model reflexive structures as described by social
theories (as the TSSO - see below).
A Petri Net as a Token
- A net that contains nets as tokens is called a system net.
The net tokens are object nets. Nested hierarchies with more
than two levels are possible, even more, any reference structure
including cyclic and hence reflective ones are allowed. In the simple
example of Figure 3 place p1 of the system net
contains an object net as a token. The inscription
on:channel(42) of the transition t in the system net
is a so called down-link to the object net. The corresponding
up-link :channel(x) in the object net is inscribed
to transition e. Up-link and down-link constitute a
synchronous channel, a communication means in reference nets.
Both transitions that form the parts of the synchronous channel may
only fire synchronously. When firing, it is possible to exchange
information from one transition to another (bi-directional). In the
example, t and e may only fire together and if they
do so, the net token is bound to the variable on and the
value 42 is passed to the variable x. Note, that the Petri net
concept of a variable differs from the one in programming
languages, and is related to the variable concept of predicate
logic. Variables are only bound locally. In more complex nets
several down-links and up-links may match. They are bound at runtime
as a part of the token-to-variable binding search of the Petri net
simulator RENEW (Kummer et al. 2004) which is an
open-source run-time engine for Petri nets based on Java. RENEW allows for modelling, execution, and simulation
of Petri nets (cf. the tool's homepage www.renew.de).
Modelling: Being Precise
- One of our project's aims was to find out what Petri net-based
modelling of social theories can perform with regard to the evaluation
of theories. In short, the results are as follows.
- Computer science is forced to incorporate detailed information in
formal models instead of relying too fast on more elegant but
reductive models. The sociological grounding through
continuous and consequent feedback for almost every step of modelling
not only increases the realism of the evolving social system of agent
programmes, but also raises the probability of grasping essential
qualities of social systems.
Furthermore, the precise sociological grounding can casually open new
ways to approach some principle problems of socionics.
- Sociology is forced to explicate theorems and axioms, that are
hidden in social theories, because the somewhat un-sociological
construction focus of the computer science raises specific questions
which highlight theoretical areas unmarked by routines of sociological
Relations between concepts and statements - e.g. hierarchical,
process and recursive orders - are shown more clearly and distinctly by
means of the strict logic order and the graphics of Petri nets (sometimes more
than the linear textual account is able to). The same applies to similarities
and differences between complex interrelations (or argumentations) between two
theories or even within one theory.
Furthermore hidden gaps in the underlying theories can be
identified, thus providing an additional positive side effect.
Evaluating Social Theories by Analysing the Petri Net Model
- We use Petri nets in order to obtain an operational model. This
makes two approaches possible:
(a) transferring the socionic elements directly into the
multi-agent system architecture without the risk of adulteration of
the social concepts (see below)
(b) providing a kind of theory
simulation to validate the TSSO.
- Below an example for a
qualitative theory simulation is given. Here we check by simulation whether the theoretical description of a
social unit is rich enough to create those kinds of dynamics which are
foretold by the theory.
- Due to the mathematical character of Petri nets a formal evaluation
by analysis is possible. This includes static as well as dynamic
aspects. Analysis further divides into two possibilities, namely
analysis by analysing the net structure and verification of the entire
state space (model checking). The dynamic analysis of a Petri net
allows for an inspection of liveness (absence of actions that cannot
be taken), boundedness (finiteness of the state space),
reachability of a given state and some more. A typical questions is:
"May a desired state be reached from a given state?"
- The striking examples of static analysis of Petri nets are invariants
and structural boundedness. Unlike usual programming languages, Petri
nets allow for a computation of these properties. Of particular
interest are the so called T-invariants. T-invariants provide
information which actions (modelled by transitions) have to take place
in order to restore a given (initial) state of the system. The computation of
the boundedness of a model may answer the question if, for example, an
arbitrary accumulation of tokens is possible.
TSSO: The Theory of Social Self-Organisation
- The theory of social self-organisation
(TSSO) is a middle range theory of self-organisation in institutions
of education (published in Langer 2005a). Its core concepts and
propositions are drafted in the following sections.
- The TSSO conceives
self-organisation as rearranging social structures,
which includes all processes and actions that social units generate,
build up, stabilise, modify, and even disintegrate. Hence,
self-organisation is used synonymously to structuration, a term
invented by A. Giddens (Giddens 1984) (The function of references to
sociological theories in this text is to show how the TSSO is
related to existing sociological theories, to accent its level of
abstraction, and to give an idea about possible relations even
between seemingly incompatible theories.). Both terms mean
influencing structures by structures.
- The TSSO consists of three main parts: Firstly, it proposes a general
dynamics of constitution, with which every social unit
(re-)creates and (re-)produces itself. Secondly, it
provides a dynamics of structuration, that arises whenever social
units get to deal with one another and with a problem they define.
Finally, the theory reconstructs four main structure dynamics,
conceived as typical results after iterated altercations.
The Dynamics of Constitution
- The dynamics of constitution is modelled
as a high-level Petri net. The basic entity of the TSSO is the social
unit. Its main activities are modelled as the net shown in Figure 4. The elements of the net model
(places and transitions) are taken directly from the textual
description, e.g. the activities (accept practically,
expect regularities, ascribe, symbolise reflexively etc.) are
modelled as transitions; the main concepts (e.g. stable
regularities or structural
capabilities) are modelled as places. The net model is explained in the
following. Note that the following description does not explain the
usage of the high-level net features of RENEW, like arc- and channel-inscriptions. For an
introduction cf. (Kummer
The Petri Net Model of the Dynamics of Constitution
- The social dynamics of constitution is a mechanism consisting of
three main factors. The first factor points out that social units
basically encounter their environment (a) by letting most of it
be as it is, (b) by involving own actions in and adjusting them to
existing social regularities, processes and structures, and (c) by
transintentionally reproducing parts of it, following a pattern like:
"one may not want to strengthen the economic system or to support
slaughter by buying sausages, but in fact one does so". These three
characteristic and coherent ways of reproducing or at least
not-resisting existing social structures and processes are called
- This concept, on the one hand, emphasises
that any social practice is valued - even values itself -, beacause it
is accepted (and accordingly acknowledged) by treating it as if it was
worth being treated in this particular way, and by drawing
distinctions between certain stressed and certain neglected parts of
social practice (cf. Bourdieu 1993). One can underline this
aspect by changing the term into (acknowledging or) accepting
practice or even accepting behaviour. On the other
hand, practical acceptance as a concept allows to explicitly include
all receptive or even passive forms of behaviour into a theory of
social action, so that an actionistic misinterpretation of
social reality can be avoided (a theoretical step demanded by Sofsky (1996) and Joas (1992)).
- This activity is modelled by the transition encounter
environment (in the upper left part of Figure 4).
The transition has no pre-conditions and therefore it is always
enabled. Firing of the transition causes a state change by adding one
new token on the place encountered parts of social practice
and one token on the place social unit - describing the
social unit related to the encountered parts of social practice. The
process of practical acceptance is strongly related to the process of
encountering the social environment. In the model this is reflected:
The post-conditions of the transition encounter environment
are the pre-conditions of the transition accept practically.
Firing of the transition accept practically generates new
practical acceptance. Note, that the concept of
practical acceptance is twofold - it is the same time a process
and a result. This dual notion is typical in the socionic
context and is reflected directly by the Petri net model using the
duality of active and passive elements which is inherent to the
Petri net theory.
- Now acts of accepting behaviour (i.e. practical acceptance) usually vary and
can get very different. The behaving social units have to accept this
practically, if they don't want to lose their ability to be accepted by other
social units. Thus, they begin to evaluate bygone and to expect coming
regularities of behaviour, estimating how stable those
regularities are. They then ascribe different stable regularities of
behaviour (structures, processes) to certain social units (modelled by the
transition ascribe). Once this is done, those social units do dispose
of social capabilities. Such capabilities - forms of behaviour expected by
certain social units to be performed by certain social units in a regular way
- are properties or qualities of these units, and similarly they are parts of
their structure. This complex is conceptualised as structural
capability or capability structure, which is the second factor of
the social dynamics of constitution.
- There are two main efforts of this
concept according to sociological explanation. Obviously it integrates
an actor-attribute-highlighting concept of capability (Coleman 1988 1990; Bourdieu 1987; Putnam 2001) - as the basis
of social power and any form of social capital - and a
relation-and-regularity-emphasising concept of structure
(cf. e.g. Giddens
1981) as two views onto the same object. In addition, the
concept of structural capability relates some so far fragmented
theoretical models; e.g. the relation between regularities and
1984) is explained, and the similarities between different types
of capital are reconstructed: the essence of capital is the capability
- The process of evaluation is modelled by the transition
evaluate behaviour, which operates on the current marking of
the place practical acceptance and stores the outcome of this
evaluation as a token on the place stable regularities. The
ongoing process of evaluating of the stability degree of the tokens on
place stable regularities is modelled by the transition
estimate stability. Here the Petri net concept of
concurrency is of special interest. Nevertheless the fact that the
dynamics of constitution is presented in a sequential way and that the
explanation of the Petri net model follows this sequence, the
dynamics is not sequential at all! For example the activity
estimate stability is independent from the activity of
practical acceptance and even independent from estimation
activities concerning a different kind of stable regularities. This
independence is stated explicitly by concurrency of activities in
the net model and helps in the understanding of the TSSO. The
transition ascribe takes a token from stable
regularity and one token from social units to model the
activity that one stable regularity is ascribed to a certain social
unit. As a result a new token is generated on the place
ascribed regularity expectations. This is a direct
example for the direct transformation of a central TSSO-theorem into
the net model. The similarities in the evaluation activity - with
respect to practical acceptance and stable regularities - are
reflected by the model: ascribed regularity expectations are
expected (transition expected) which generates new tokens on
the place structural capabilities which are again subject to
an estimation process.
- As social structures and capabilities are changeable in large amounts and as
they are not directly visible, actors are coerced to stabilise and visualise
them, if they somehow want to get (and stay) capable of acting socially. They
do so by symbolising structures and capabilities (or parts of them) by
adding signs to them. The results of these symbolising acts accumulate
to the reflexive symbolism or the symbolic reflexivity of a
- This is the third factor of the dynamics
of social constitution. It is called reflexive, since the social
world relates to itself in this specific manner of mirroring by signs
1994). This activity is modelled by the transition symbolise reflexively which operates on tokens
of the place structural capabilities and
on signs. The result is a reflexively
symbolised capability structure, which is in fact a social unit
generated onto the place social units.
Reflexive symbols and symbol-mediated reflections are the only way in
which social reality appears explicitly and can get caught, thought,
communicated about and intentionally influenced by itself,
respectively by the acting and reflecting units it consists of (this
means a specific type of basic social self reference (Luhmann 1984, 1997) which is
regulable from almost non-reflexivity to, e.g. the degree of
reflexivity postulated by Beck and Giddens for the second
modernity). Every reflexive symbolism only illuminates a small
selected part of all structural capabilities, though.
- The concept of symbolic reflexivity
allows systematising well known sociological core concepts. Norms and
1992), e.g., have in common that they are symbolised expectations
on regular behaviour, positions (Popitz 1981) are symbolised units of fixed
structural capabilities - and for this reason of course parts of
social (capability) structures -, whereas titles and names (Bourdieu 1987, 1993) are
symbolised ambulant structural capabilities. Furthermore, the theory
inter alia shows that symbolic capital must be more fundamental than
economic and cultural capital (which ultimately are but specified
sorts of social capital, which is nothing else than structural
capability); that reflexivity is a basic feature of all social units
(hence it is inauspicious to characterise an era as a reflexive
modernity); and consequently it conceptualises symbolic
reflexivity as a social act and releases it from being tied to the
consciousness of single persons.
Evaluation of the Model
- In this article, we often use the terms social unit
when it comes to the subjects of social processes. We do so because of widely
spread understanding routines. But we do have an elaborated concept of what a
social unit is. We call it practical order
(respectively order of practice). Depending on what perspective one takes up,
a practical order can be seen as a structure, a process, a society or group,
or even as an actor. This concept allows not to prejudge certain qualities of
whatever becomes subject or object in the social world, so the forthcoming
multi-agent architecture does not need to handle with conceptually separated
different units. To put it in a nutshell, you can say all is practical
order (like all is data from Strauss' and Glaser's Grounded
Theory) - or, as for modelling multi-agent systems, all is agent,
whereas the term agent does no longer have a hidden person
connotation. The hypothetical slogan all is practical order is
empirically grounded: it reconstructs, that people fundamentally can treat all
social units as actors (the curriculum craves), as a differentiated
sociality (the instructions in the curriculum are contradictory), as
a structure/capability (this curriculum enables us to follow
international standards), or as a process/activity (students go
through a curriculum). The slogan is theoretically grounded: Just take a
look, e. g., at all the units theories treat implicitly and explicitly as
actors! For these reasons it became necessary to create a concept for
all units being treated as actors.
- We want to point out that our theory does not claim any prerogative
for macro or micro phenomena, for actions or for structures, for
persons or societies, for systems or for frames etc. etc. They all
are but varieties of practical orders; the rest is up to
subject-adequate specification of the theory.
- As a result of the modelling effort we like to point out the following
similarities concerning the inner structure of the TSSO which in fact
can be seen very clearly already from the graphical representation of
the Petri net model. The activities of the constitutional dynamics,
namely: accept practically, ascribe, and symbolise
reflexively share certain similarities (Note that these
similarities are visualised by the symmetries in the net layout.):
- Each activity is embedded into forms of social practice:
encountered parts of social practice, behaviour
expectations, and structural capabilities, respectively.
- Each activity is related to that social unit (or the
sign) that is referenced by it.
- Each activity generates archetypes of social structures:
practical acceptance, ascribed expectations, and
social units, respectively.
- Each archetype of social structures is transformed into a stable
form (stable regularities and structural capabilities)
as a result of an evaluation process (modelled by the transitions
evaluate behaviour and expect regularities,
- The elements of social structure (stable regularities and
structural capabilities) are both subject to change, modelled
by the transition estimate stability, which relates the
actual environmental forms of social acceptance to the current
regularities constituted by the social unit.
- The formal analysis of the Petri net structure reveals several
interesting insights. Here we name two of them:
These facts were of interest for the social scientist of our project,
since they imposed questions which helped to improve
- All places in the model are unbounded. This indicates that the
TSSO model has no mechanism to "forget" data.
- T-invariants include only both transitions estimate
stability. This indicates that the system has a permanent
dynamics since in a stable state only observing behaviour is
The Dynamics of Social Structuring
- The outlined concept of a dynamics of
social constitution specifies the system-theoretical idea of
autopoiesis according to social phenomena. It grasps an
almost completely transintentional and therefore utterly striking
mechanism of social (re-)production and self-organisation.
For the concept of transintentionality cf. (Greshoff et al.
2003). The consequences of constitutional dynamics can be shown
by taking a closer look at what happens when multiple social units
deal with one another and with a problem or an issue they are
interested in. It is easy to see that the (re-)production
process of a social unit is related to those of other units. The
system generated by the totality of all social units is modelled in
Figure 5. Note that the
constitution dynamics is not only a process of re-production for the
social unit of actual interest. It also is an auto-poetic process
with respect to the whole system generated by the totality of all
social units. Here the use of a reflexive and recursive Petri net
formalism is of special importance: reference nets. The place
social units contains the tokens that
model those social units which are participating at the quarrel. The
tokens are Petri nets, that share the structure if the net shown in
Figure 4. The initial state of the
model is set by the transition init,
where the inscription su: new su denotes
the creation of a new instance of type su (social unit).
The Dynamics of Social Structuring Modelled with Reference Nets
- This dealing with in the TSSO is called
Auseinandersetzung, which roughly can be translated as
quarrel, but means a mix of quarrel, debate, treatment,
handling and even struggle. Quarrels (not only conflicts) are
understood as the motor of social change, development, and decline.
- Any occurring quarrel unavoidably runs through a specific
dynamics of structuration. Whilst the constitutional dynamics
predominantly originates and reproduces social units, the
structurational dynamics rocks the boat: depending on what shape it
takes, it provides all kinds of social changes, from imperceptible
modifications to revolutions, from stabilisation, conformation and
encouragement to distraction, dissolution and destruction. The
dynamics of social structuration consists of six, in order to the
course of the proceeding quarrel, chronologically arranged factors.
And these factors are nothing else than specific constellations of the
topical problem and the constitutional dynamics of all those social
units that are involved in or related to the quarrel - or more
precisely, of the factors of their constitutional dynamics.
The six factors are:
- Expectations on the effects of the quarrel
- Practical (non-symbolic) of the issue of the quarrel
- The relation between new symbols the units produce during the quarrel
- The relations between the elements of the constitution dynamics
the involved units reproduce themselves with
- The mutual ascription of structural capabilities
- The relation between practice and symbolism in this quarrel
- Every factor can switch between either leading the quarrel to have no
effects on the institutional capability structure the quarrel takes
place in, or to have such effects (which is self-structuration). In
the following example one typical result of iterated quarrels will be
shown, where almost all factors are switched to the latter case.
The Hierarchy-Increasing Dynamics
- The hierarchy-increasing dynamics is subjected to the following
conditions. A steep hierarchy is already established. This is easily seen
by the extremely unequal distribution of two sorts of
structural capabilities: formal-legal capital and political capital.
There exist deep gaps between, e.g., on the one hand the amount and
degree of actualisability of the capital a ministry of science
disposes of, and, on the other hand, the amount and actualisability of
the same sorts of capital owned by universities. Another such gap can
be found between chairmanship and faculties, or between professors and
students etc. Now as formal-legal capital and political capital are
used to prevail in quarrels and to organise social structures, the
respectively formal highest positions and politically most versed
actors, which are the same, do have hands over university structures
and capabilities. Moreover, they receive practical and symbolic
acceptance for influencing, altering, preserving and attending those
structures and capabilities - which raises the amount of their
capital and makes it worthwhile.
Changes in the Capability Structure through a Hierarchy - increasing Dynamics
- Figure 6 is a visualisation of a
transition between two states during a RENEW-simulation of the
Petri net system given in Figure 4
and 5. "Normal" professors or students (named
su1, su2, and su3 in
Figure 6 where arrows indicate the
capability structure) contrarily deny disposing of capabilities which
are relevant for self-administration, hardly receive practical or
symbolic acceptance for self-administration work, and so they tend to
dislike it while considering it being totally separated from or even
obstructing scientific work - and therefore quite useless (depicted
as self-loops in Figure 6 - the small
arrow tips indicate minor relevance of this capability). As a result,
they abandon as much (self) administrative work as possible to leading
positions (named su in
Figure 6). And with the
administrative work they leave their administrative capability up to
the top positions, too, while administrative capability is a mixture
of formal-legal capital and political capital. Thankful for "good
dictators" most of the time, scientific university workers provide
the actors on the formal top positions regularly with capabilities up
to an extent, which legally neither is envisioned nor tiled.
- In accordance with the Petri net model in Figure 4
and 5, the hierarchy-increasing dynamics transforms
the capability structure in the way
Figure 6 sketches it. The structural
capabilities relevant for self-administration purposes are transformed
into capabilities for the leading position.
- This hierarchy-increasing tendency is tightened by the fact that
the lower scientific actors stand in the formal hierarchy, the more
isolated they are - which means, they do not dispose of a
meta-capability-structure consisting of solidarising skills like
abilities to organise, communicate or cooperate. But high-positioned
actors do dispose of it: it is identical with their structural
capabilities (= capital), which confer them with rareness, a clear and
steep internal hierarchy, and a huge supremacy, that means close
boundaries, to the legally subordinated positions and actors. And this
makes them highly capable of organising themselves and of using divide et
- Beside theory integration and modelling,
a further root for developing a theory of social self-organisation was
empirical research about self-organisation and decision making in
universities. For an early inspection cf. (v. Lüde et al. 2003),
concluding results are published in (Langer 2005b). Merely unknown
underlying informal mechanisms of self-administration and
self-organisation were discovered, e.g. (a) a conservation dynamics
that keeps in balance top down initiatives with symbolic protests,
business competition, rivalry, and trust building; (b) an intrinsic
hierarchy-increasing dynamics (which can show that the formal
strengthening of leading positions in german universities is not very
innovative); and finally (c) two different dynamics of making
invisible and of paralysing all the knowledge and power that
specifically could be applied for using self-organisation mechanisms
reflexively to achieve volitional structural efforts.
- The results of the university study (and,
additionally, the results of an investigation about institutional
reorganisation by implementing feedback procedures in schools,
et al. 2005)) were integrated with the outline of a general
theory of social self-organisation (see Section 2.1 above) by analysing them on
similarities. In this way, the general theory got empirically
grounded, differentiated, and corrected, and the empirical results
were theoretically rearranged and explained. The outcome of this
procedure is a middle range theory of self-organisation in
institutions of education (published in Langer 2005a).
Agent Systems Following the TSSO Approach
- In this section we describe how the social concepts of the TSSO are
transferred to a socionic MAS architecture called SONAR that uses
and enhances the design of our former architecture MULAN. The main
feature of SONAR is the uniform treatment of social concepts as
proposed by the TSSO.
5.1 Multi-Agent Systems
- Today, agents and multi-agent systems
(MAS) are one of the most important structuring concepts for complex
software systems (cf. Jennings 2000). By including attributes
like autonomy, cooperation, adaptability, and mobility, agents go well
beyond the concept of objects and object-oriented software
- One of the aims of our project is to develop executable models
(i.e. programs) of agents and multi-agent systems that directly
incorporate the ideas of the selected social theories. In order to
reach this aim it is necessary to avoid a bias on which agent
architecture is well suited or which agent development style should be
used. We chose to delay this decision as long as possible. This is
done by a seamless further development (refinement, composition and
coloration, i.e. the attachment of algebraic annotations to the net
elements that specify the net's behaviour) of the Petri net models
gained by modelling the theory. The further development is seamless
because the modelling paradigm is not changed as it would be the case
when using ad-hoc graphics or a software modelling language like the
UML. The objective of the modelling process is twofold: first, to
identify the agents, i.e. the active elements of the theory
models and second, a collection of (interaction) processes that
describe the interdependencies of the active elements.
- A common, but misleading procedure might have been to only identify
actors as agents and to attach other (on first glance passive) social
entities like norms (to recall a popular example) as mere attributes
to the actors.
As our research has shown - and as it will be exemplified in the
paper - there is no justification to constrain the set of agents to
actors. A widened scope leads to simple and elegant models of society
that, nevertheless, offer adequate explanational power.
The Multi-agent System MULAN
- The multi-agent system architecture
MULAN (Köhler et al. 2001;, Duvigneau et al.
2003) is based on the nets-within-nets paradigm, which is
used to describe the natural hierarchies in an agent system. MULAN is implemented as a reference net system using
RENEW. MULAN is compatible to the FIPA specifications (Foundation for Intelligent
Physical Agents 2005) and thus an open system that can be
connected with any other FIPA compliant agent system.
- The overall structure of MULAN consists of four levels:
- The organisational level defines the communication and mobility
channels in the system (cf. Köhler et al. 2003).
- The platform level hosting the agents and providing an AMS
(agent management system) and a DF (directory facilitator) - details
can be found in (Duvigneau et al. 2003).
- The agent level describes the internal message processing. An
agent must be able to receive messages, possibly process them and
generate messages of its own. The agent may exchange messages with
other agents via the platform. The central point of activity of a
such an agent is the selection of protocols and therewith the
commencement of conversations. The protocol selection can basically
be performed pro-actively (the agent itself starts a conversation)
or reactively (protocol selection based on a conversation activated
by another agent). Both kinds of a conversation are influenced by
the knowledge of an agent. In simple cases the knowledge base can
be a database, or - more advanced - an inference engine (cf. Köhler et al.
- The interaction level is defined by interaction protocols. The
variety of protocols ranges from simple linear step-by-step plans to
complex dynamic workflows (cf. Cabac et al. 2003).
SONAR - Agents as Social Units
- There is a conceptual problem in MULAN as in almost every MAS architecture. The
central problem of any ordinary MAS is, that the agent is the dominant
category. To see why this is problematic consider the process of
coordination. Coordination of a group of agents generates joint
intentions/commitments. The problem here is that joint
intentions/commitments are not a part of any of the group's agents.
They are a (macro) concept beyond agents, i.e. beyond the micro level
(cf. also the discussion of Castelfranchi and Conte 1995). Such an
additional macro concept does not fit to an actor oriented approach
and complicates the design.
- The TSSO helps us to overcome this problem. The
proposed solution is our SONAR MAS architecture, that enhances
For the SONAR architecture we adopt the TSSO view. The fundamental
concept of the TSSO, practical order, may denote any
socially relevant concept, e.g. a structure, a process, an actor, a
society, an institution, a property and so on. We claim that it is
necessary to directly translate this concept to first order objects of
agent systems, thus to map it to the agent concept.
- This approach differs radically from the usual way of only mapping
actors to agents. In SONAR, actors (agents in the classical sense)
are not chosen as the primary architectural entity because this might
have the consequence that any kind of social structure is a
second-order concept. Instead the SONAR architecture is designed
along the first-order concepts of social practice, structural
capabilities, and symbolic reflection which are related in the
dynamics of constitution.
- To put it in a nutshell: A SONAR agent is not defined as a goal
directed entity. Instead, any system of rules generating social acts
(here: structural capabilities) is considered as a SONAR agent.
This has the consequence that not only actors are agents, but also
role models and the results of coordination processes (the joint
commitments etc.) are agents in SONAR.
System of SONAR-Agents
- As an example cf. the multi-agent
system of Figure 7 taken from
et al. 2005). Each boxed net is the abstract representation
of one SONAR-agent. In
Figure 7 e/e denotes
evaluate and expect; e.s. denotes
estimate stability; a/s denotes accept,
ascribe and symbolise which are the main
activities of a social unit in the TSSO. The dashed arrows
illustrate the ascribed regularity expectations of the TSSO. The
SONAR-agents accept practically that the agent p4 is involved in
the process improvement of lectures. This acceptance is stable
and has generated a structural capability, also named
improvement of lectures, a next step in might be that the
structural capability is symbolised resulting in a new entity, say:
assistant dean for lecture quality.
- The agent systems need to be adaptive at run-time to a high degree.
This and the use of the same concept - agent - at all levels of the
system leads to further requirements:
- Creation and Adaptability of agents at run-time - this entails
the adaptability of the entire agent system at run-time
- Agent system adaptability also means adaptability of hierarchies and
nestings in the agent system
- Use of identical concepts and mechanisms inside and outside of
the agents - more precisely, the discrimination between inside
and outside becomes blurred (because the same concepts are used)
- As stated before, platforms in a full featured SONAR system may act
like agents and encapsulate the hosted agents. It is therefore no
problem to implement e.g. a holonic MAS using SONAR agents. The
logical consequence of this approach is to exclusively use these
platform agents as agents in the MAS. Following this idea leads
to a dynamically reconfigurable MAS structure, i.e. a new hierarchy
level may be introduced at run-time simply by creating a new
(platform) agent and migrating other agents into it.
- Since the inherent complexity of dynamic
architectures demands for formal analysis, the choice of Petri nets
seems appropriate not only as the modelling but also as the
implementation language (like in SONAR). An
application of formal techniques to the analysis of an dynamic
architecture in the context of mobile agents can be found in (Köhler and Rölke
Outlook and Perspectives
- In this paper we presented our recursive research that interrelates
computer and social scientists' perspectives on artificial societies.
The social scientists' perspective is the theory of social
self-organisation (TSSO). The TSSO as an empirically grounded theory
of the middle range for social self-organisation expressed and
validated using a high-level formalism, namely Petri nets. The
presented Petri net model formalises the computer scientists'
- The formal model of the TSSO allows, on the one hand, for the analysis
of the inner logical structure of the theory, and on the other hand,
for the derivation of the dynamics of social structuring from the
dynamics of constitution.
- But as the core of the TSSO is a general theory of self-organisation,
it can be applied to natural and artificial societies as well.
In the context of real societies the TSSO helps to understand the
processes in institutions and contributes to the attempt to manage
them. Current work of the ASKO project applies the TSSO
to the empirical field of universities. Additionally, we will extend
the TSSO to a general theory of social processes.
In the context of artificial societies the Petri net description of
the TSSO provides an integrated formal model in a mathematically exact
and coherent way. By means of these attributes the model helps to
improve the system architecture since it avoids an eclectic approach
where new concepts of sociality are introduced without any
- Furthermore, for the design of a MAS architecture named SONAR the
development of the Petri net model avoids the bias that is unavoidable
if some concrete architecture elements or even the programming
language is chosen in an early design phase. In SONAR agents are
not chosen as the primary architectural entity because this might have
the consequence that any kind of social structure is a second-order
concept. Instead the SONAR architecture is designed along the
first-order concepts of social practice, structural
capabilities, and symbolic reflection the dependencies of which
are related in the dynamics of constitution.
- Note that the basic concepts of the TSSO model are not restricted to
multi-agent systems - they can be applied to any kind of
self-organising or -modifying system architecture
(cf. Cabac et al. 2005).
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