Distributed cognition and affordances

From:
Article in press:
Cognition & Pragmatics, 00, 000-000.
Distributed Cognition, Representation, and Affordance
Jiajie Zhang
Vimla L. Patel

http://acad88.sahs.uth.tmc.edu/courses/hi6301/affordance.html

The most interesting idea of the paper is how they suggest to describe affordances: either as the constraints or as allowances of actions. This is well in accordance of the theoretical framework we have followed.

In terms of the theory of distributed representations, affordances are distributed representations extended across the environment and the organism. The structures and information in the environment specifies the external representational space. The physical structures of the organism and the structures and mechanisms of internal biological, perceptual, and cognitive faculties specify the internal representational space. The external and internal representations together specify the distributed representational space: the affordance space. The external and internal representational spaces can be described by either constraints or allowable actions. Constraints are the negations of allowable actions.

They refer to certain affordance types, i find this one interesting, because the same example has been brought in itersubjectivity studies:
Cognitive Affordance
Affordances of this type are provided by cultural conventions. For example, for traffic lights, red means “stop”, yellow means “prepare to stop”, and green means “go”.

Reconceptualizing Activity Theory in distributed settings

The learning environments cease to be primarly tutor-defined and well controlled spaces, thus, the user-selected variability in the learning environments has to be considered as part of the learning-design. For instasnce, Kirschner et al., (2004) suggest a new affordance based and learner-centered interaction design model. New competencies would become important both for the students and the educators, such as the ability of finding and choosing the appropriate learning tools and systems among social software, prognosing the educational affordances of these systems, composing the distributed learning space from the set of tools, collaborating in distributed spaces for sharing knowledge and regulating one’s learning with the remote others who might perceive the different concept of the how this learning environment might favour their activities.

The Activity Theory model has recently been of continuous interest in explaining the processes taking place in the learning communites. According to Leontjev (1975/78) and Kuuti (1995), any shared activity can been defined through the shared motives that form the object of the activity for the community, the activity is performed by the subjects of the community; the activity consists of goal-directed actions conducted by the community members, the goals of the actions are realised by performing certain operations using the tools (material- or knowledge-tools, language) of the community as the mediating devices. For Kuuti (1995) the learning environments can serve at the same time as the mediating tools enabling the manipulations with the objects, aiding knowledge construction and communication, but also as the object of the activity that turns implicit community knowledge externally observable. The latter is especially characteristic to new Web 2.0 software (e.g. social bookmarking, blogosphere etc.). The object of the activity can be realised as the outcome of the activity, knowledge artifact, community practice etc.

For defining the elements of collaborative activities in social-software supported learning environments at least two levels of the activity should be considered: the Activity System level (Engeström, 1987), and the operation level (Kuuti, 1995). The Activity System model (Engeström, 1987) describes general information flows at the community level within or between the communities. According to Engeström (1987), the object of the community brings forth the division of labour and the alignment to certain rules that constrain the availability and the use of possible operations and tools. In any Activity System the contradictions emerge between the subjects about the object, the division of labour, the alignment to the community rules, and the application of tools. The Activity System model suggests ‚Object-activity‘, ‚Rule-producing activity‘, ‚Subject-producing activity‘, ‚Instrument-producing activity‘, and ‚Central activity‘ to take place in the system.

Operating in the Activity System evokes different patterns of coordination emerging in groups of individuals engaged in joint action with material and informational systems in their environment (Greeno, 2006). Engeström, Engeström and Vähäaho (1999) distinguish the activity systems operating in teams or networks, and the activity systems emerging in the work communities. Teams and networks are typically understood as relatively stable structures, often assigned by instructors, sharing the same objectives and mediation tools. The subjects in work communities however are involved in workflows that consist of combinations of people, tasks and tools that get connected at relatively short duration. Yet in their basic pattern, these workflows are continuously repeated and evolving. Engeström et al. (1999) describe these temporal trajectories of successive task-oriented combinations of people and artifacts emerging within or between activity systems as knotworking situations. The notion of knot refers to a rapidly pulsating, distributed and partially improvised orchestration of collaborative performance between otherwise loosely connected actors and activity systems. Knotworking situations rely on fast accomplishment of intersubjective understanding, distributed control and coordinated action between actors. Since now the e-learning in Web 1.0 has been exploiting the activity patterns that form around shared objectives and joint medium in which learning was centrally controlled by facilitators. However, the e-learning in Web 2.0 would rather be knotworking between loosely connected learners using distributed tools. Engeström et al. (1999) assume that in knotworking the tying and dissolution of a knot of collaborative work is not reducible to any specific individual or fixed organisational entity as the center of control, the locus of initiative changes from moment to moment – the center does not hold. They suggest bringing the analysis of activity systems at knot level. In knots the subjects get connected via mediation tools and perform actions upon certain shared objects using or creating artefacts.

How do the subjects perceive themselves and the others in object-directed interaction in knots, could be described by the notion of „affordances“. Gibson (1979) defined affordances as the opportunities for action for the observer provided by an environment. However, as assumed by Gaver (1996) affordances are primarily facts about action and interaction, not perception. This contrasts with the common impression that affordances refer to—approximately—situations in which one can see what to do (Gibson, 1979). The mainstream view to the affordances in educational technology settings considers them the objective properties of the tools perceptable in the frames of some activities, suggesting that tools have concrete technological affordances for certain performances that can be brought into learner’s perception with specific instructions (Norman, 1988; Gaver, 1996). Neisser (1994) elaborated Gibson‘s affordances distinguishing three preceptual modules: i) Direct perception/action, which enables us to perceive and act effectively on the local environment, ii) Interpresonal perception/reactivity, which underlies our immediate social interactions with other human beings, and iii) Representation/recognition, by which we identify and respond appropriately to familiar objects and situations. Kreijns, Kirschner, and Jochems (2002) have defined social affordances as the “properties of a collaborative learning environment that act as social-contextual facilitators relevant for the learner’s social interaction. Neisser’s interpretation, however enables to consider also the interpersonal perception between subjects in action as the source of affordances at social and regulative domains. Kirschner (2002) defined educational affordances as those characteristics of an artifact that determine if and how a particular learning behavior could possibly be enacted within a given context. The contextual aspect of affordances relates with the artifacts and meanings. Thus, instead of relating affordances objectively with the software they should be related with the knots of the Activity System where subjects must realise how they perform joint actions with artifacts and tools in order to accomplish their shared object. Cook and Brown (1999) assumed that affordances are dynamic – the ongoing interactions with the environment and objects, where our previous knowledge applied during the activity helps us to evoke noticing of certain aspects, affordances, and knowing how these affordances could support the activity. This assumption supports the Engeström et al. (1999) view of the dynamic nature of knots in the Activity system.

Greeno (2006) has suggested that two components: an interaction analysis of the conversation including close attention to its turn taking, responses and contributions, and the semiotic structures of information that they constructed in the conversation should be taken into account when analysing Activity Systems. He suggests to apply both representations and representational practices in the same analysis of activities, assuming that when researchers shift the analysis of knowledge construction to the level of the Activity System, they include explanations about the various participants in the activity, and they analyse ways that individuals are positioned in the participant structures of interaction, and how that positioning contributes to generation of information structures.
The contradictions in activity systems arise and must be worked out at operation level in order to realise the object of the community (Kuuti, 1995). Thus the action and operation level elements of activities must be defined in order to explain the functioning at the activity system level. To work on shared learning objectives, activities in the communities must be dialogue-mediated for creating intersubjective knowledge, and consist of actions where learners jointly manipulate tools and artifacts or create shared knowledge artifacts. Laurillard (1993) has developed the conversational model between the teacher and the student where she distinguishes dialogue about the content, the manipulable actions, and the dialogue about the manipulable actions.

Laurillard framework was modified in order to model actions in the distributed activity-space for the collaborative object-oriented virtual activity involving two subjects (e.g. facilitator and the student, or n number of students).

The actions and operations in distributed activity space are conducted via the mediation of different tools. Typical actions what might take place while interacting with the tools, content and other groupmates are communicative (generating content; regulating content-relevant actions, regulating activity processes, regulating social atmosphere) and manipulative (operating with artifacts and tools). The operations conducted at each action, combined with the subjects and artifacts involved in that action of the activity enable to suggest which are the affordances of that knot at the certain time.

Engeström Activity system is defined for modelling face-to-face work settings, where people communicate directly, and do not need mediating devices for communicatively discussed activities related with the common objects, rules, tools and subjects in the work community. For modelling the Activity System for distributed virtual settings it is reasonable to modify Engeström (1999) model. The Distributed Activity System model distinguishes the direct manipulative actions performed with tools and material artifacts from the indirect communicative acts in, which people develop their common objects verbally and publish them at the same time via the mediating devices by involving some material artifacts into this process if necessary. The separation of the direct actions with manipulable objects and indirect mediated communicative actions in the Distributed Activity System model would reveal the mediated regulative dimension, in which the community must come to the common ground in their rules, distribution of labour, understanding what is planned to do to realise the shared object in the form of knowledge artifact, and receive feedback about the object-relevancy of their actions. The actions described in the Laurillard (1993) framework modified for distributed systems take place in each knot of the activity and enable to predict the affordances of the knot. The dynamically changing affordances at the Activity System level could be used for the analysis of the development and effectiveness of functioning of the system.

The question is how do the affordances of the Activity system develop if „the center does not hold“, and the learners must realise common goals in Web 2.0.

Secondly, it is of interest, how do the affordances of the Activity system, predicted by the instructor, differ of the actually emerging affordances in different learning groups, and how should the instructional designs tackle with this problem.

Towards new views of analyzing networked communities

Two views of mapping networked communities prevail; networks of people and networks of content. The former is a mainstream person-based view to the community, the latter suggests that contributions in blog act as separate artifacts that convey meanings, enable meaning translability and interpretation and generate similarity-based connections between artifacts. If to follow Lotman’s cultural semiotics and translation ideas, two kinds of translations may occur: subjects that are translating on the basis of similarities, shared area of meaning; and the others who translate from the areas beyond overlapped meanings.

Artifacts form the base on which the person-based community is formed. The similarity-based translations and interpretations of artifact meaning suggest that there is a community who shares certain understandings and ideas; the translations beyond similarity are like bridges between align communities. This view suggests that it is not necessary that the connection between communities happens because there is a person who shares the identity of both communities. The artifact and translation beyond the borders will create the connections even if the interpreter from the other community has no shared identity with the community where the artifact comes from. Some types how it happens are by using something from the artifact as an analogy or metaphor, also the tunnel effect is a way of transferring meanings between communities.

From Mattew Hurst
http://datamining.typepad.com/images/bloggalaxy-3.png

The visualization does two things. Firstly, it clusters blogs according to a measurement of connectivity designed to show communities. These communities are defined by a certain amount of cross linking.

Secondly, these communities are then laid out according to how much interlinking goes on between them. Interlinking between communities is measured by observing any links between blogs in each community. The gray lines between clusters represent these inter-community links.

Upon examining the clusters, one can observe clear thematic groupings. These may be topical or cultural and locale clusters.

From
What Would It Mean to Blog on the Semantic Web?
David R. Karger and Dennis Quan
2004
theory.csail.mit.edu/~dquan/iswc2004-blog.pdf

From: Tomographic Clustering To Visualize Blog Communities as Mountain Views
Belle L. Tseng
Junichi Tatemura
Yi Wu
2005
www.blogpulse.com/papers/2005/tseng.pdf

The authors developed an interesting “mountain” view to networks.

Tomography is taken from computer tomography (CT) scan that generates 3D structure of a human body by accumulating 2D slices.
Mountain view can be seen as the “contour” of the community structure since the curve shows upper bounds of paths within the social network.

Authorities are shown as peaks, and connectors are shown as valleys.

From: Discovery of Blog Communities based on Mutual Awareness
Yu-Ru Lin Hari Sundaram Yun Chi Jun Tatemura Belle Tseng
2006
www.blogpulse.com/www2006-workshop/papers/wwe2006-discovery-lin-final.pdf

The authors use mutual awareness to discover communities.

The key idea of our approach is to (1) compute the mutual awareness as edge weight in a graph-based representation of blogspace, and then (2) use a ranking-based clustering method to extract blog communities.

We compare the communities extracted by using two different features—the baseline adjacency matrix and the mutual awareness matrix.
When using the baseline adjacency matrix, the total number of entry-to-entry links pointing from blog u to blog is used. When using the mutual awareness matrix, mutual awareness is
defined by considering both entry-to-entry link and trackback links.

We use a ranking-based method to extract blog communities from the graph representation of blogosphere. In contrast to general graph partitioning problems that divide all the nodes into groups, we are only interested in groups of bloggers who are actively communicating with each other. Since the observable links such as entry-to-entry hyperlinks among blogs are rather sparse, there are many blogs that are relatively isolated in terms of their observable links.

Assume that we have a blog of interest (e.g., the top ranked blog) and want to find a community that is represented by this blog.
Then imagine that a random walker always starts from this blog.
The random walker will visit a community member more probably than a non-member. In this way, the association score is defined between a blog and the blog where the random walker starts. Based on this intuition, our method starts from a set of blogs each of which represents a community. We refer to these blogs as the seed blogs. By comparing scores of a blog associated with the seed blogs, we decide which community the blog belongs to.

Coverage measures the fraction of edges that are intra-community. Communities with higher coverage have higher quality. This is intuitive because a larger value of coverage implies more interaction is within communities instead of between community members and non-members.

A community with a small conductance has higher quality because the number of links pointing to non-members is small relative to the density of either community members or non- community members.

Interest Coefficient is used to measure how much a community member is interested in his or her assigned community.
Intuitively, individual bloggers are supposed to spend more time within their own community. If the majority of a blogger’s actions is with members of her own community, then this is a good indication that she is interested (or involved) in this community. A high interest coefficient of a blog community as a whole, suggests that the community members are highly involved.

A real community in the blogosphere should exhibit cohesiveness. That is, a group of bloggers in a tight community should have sustained interactions over time.

Human-Centered Analysis and Visualization Tools for the Blogosphere
Xavier Llor`a Noriko Imafuji Yasui Michael Welge1 David E. Goldberg
http://www-discus.ge.uiuc.edu/discussite/2006/11/29/human-centered-analysis-and-visualization-tools-for-the-blogosphere/

Paper introduces an interesting topic-centered approach to visualise concept relations in blogosphere.

Each text of a post can be turned into a n-dimensional vector of features using text mining techniques (Weiss, Indurkhya, Zhang, & Damerau, 2006). Each feature is a word in the text—once stop words are removed—and the vector represent some sort of frequency measure for each of the feature.
ISNP (Identifying Self/Non-self Post) is an algorithm and visualization technique to create predictive models of the posts. ISNP uses the post-based vectors to learn models that describe and predicts what post belong to a feed.
Once the models are learned, we can use them—for instance—to predict pertinence to a feed given a blog, compare multiple feeds to measure degrees of topic overlapping, or simple visualize the key elements that identify self in a post.

Radial map of the key terms involved in the ISNP models for each of the posts. Different posts are displayed in different colors. The area provided by the measure of relevance of the terms provide a qualitative measure of model overlapping for the different post.

From
webdiis.unizar.es/~ftricas/Articulos/Blogosphere%20community%20formation.pdf

Using content requires a vector space representation, usually term frequency/inverse document frequency. This representation is usually highly-dimensional, much more so than using links to other members of the set of webs that is going to be studied.

From: R. Klamma et al., 2006: Cross Media Social Network Analysis
R. Klamma, M. Spaniol, Y. Cao, M. Jarke: Pattern-Based Cross Media Social Network Analysis for Technology Enhanced Learning in Europe, W. Nejdl, K. Tochtermann (Eds.): Innovative Approaches to Learning and Knowledge Sharing, Proceedings of the 1st European Conference on Technology Enhanced Learning (EC-TEL 2006), Hersonissou, Greece, October 1-3, LNCS 4227, Springer-Verlag, pp.242-256

The communication between members is realized through the exchange of artefacts. An artefact is created by a member in a certain medium. The artefacts represent the information circulating in the digital social network.

I could find few analysis which could identify the meaning-based communities and their relationships with other communities. They still lack links with the community-view in the sense of identifying the layer of subjects on the basis of meanings.

There are some SOM based methods to analyse the topic-centeredness in the communities, but they illustrate cells with content rather than the structure of the community on the basis of meanings.

Political Blog Analysis Using Bootstrapping Techniques
Fritz Heckel, Nick Ward
www.cs.swarthmore.edu/~richardw/cs97/papers/04_Paper.pdf

Shared conceptualizations in the community indicate also the identity. They can be analysed by automated text analysis.

From Shared Conceptualisations in Weblogs
Anjo Anjewierden,
Rogier Brussee
Lilia Efimova

https://doc.telin.nl/dscgi/ds.py/Get/File-43470/Shared_conceptualisations_in_weblogs.pdf

Identify terms that potentially point to concepts.Expand abbreviations. Normalise terms. Delete implied and low frequency terms.
Once the concepts have been identified, we need to establish whether they are semantically related, at least according to the blogger. For this we rely on the assumption that there is some sort of semantic relation between terms if these terms are often used together in the same post. Find the cooccurrence.

This visualisation indicates that while both authors write about knowledge management (both weblogs are recognised as KM weblogs) they seem to have more agreement on related areas (e.g. learning and education) or specific KM sub-domains (e.g. communities or social capital) rather than sharing conceptualisations about knowledge management itself.

Artefact-Actor-Networks as tie between social networks and artefact networks

Wolfgang Reinhardt
Matthias Moi
Tobias Varlemann

In this paper we introduce the approach of Artefact-Actor-Networks that tries to connect social networks and artefact networks in order to make claims on the semantical connections between persons and manifold artefacts.

The resulting Artefact-Actor-Networks allow making claims about the ties between artefacts from multiple sources and the actors involved in their creation, modification and linkage.

To connect artefacts and actors under and between each other, semantic relations are required. Every relation in the network connects objects by a semantic context like isAutor or isRightHolder. With the help of Artefact-Actor-Networks participation in the lifecycle of artefacts as well as significant connections to involved actors will be outlined.

We consider the communication and collaboration with each tool (e.g. chat, e-mail anddocuments) as a single layer of the respective network. We unite these single layers in both social and artefact networks to consolidated networks that contain all actors and artefacts respectively.

In the context of Artefact-Actor-Networks there exist semantic relations between actors and artefacts (AArelation), actors and actors(ACT2 relation) and between artefacts and artefacts (ART2 relation).

http://artefact-actor-networks.net/2009/09/what-are-artefact-actor-networks/

object-centered nature of social networks

Interesting aspect of object-centered nature of social networks (which i also support https://tihane.wordpress.com/2007/01/01/networks-of-people-versus-networks-of-people-and-artifacts/) is discussed in the Yuri Engeström’ blog:
http://www.zengestrom.com/blog/2005/04/why_some_social.html

I think is a profound confusion about the nature of sociality, which was partly brought about by recent use of the term ‘social network’ by Albert Laszlo-Barabasi and Mark Buchanan in the popular science world, and Clay Shirky and others in the social software world. These authors build on the definition of the social network as ‘a map of the relationships between individuals.’ Basically I’m defending an alternative approach to social networks here, which I call ‘object centered sociality’ following the sociologist Karin Knorr Cetina. I’ll try to articulate the conceptual difference between the two approaches and briefly demonstrate that object-centered sociality helps us to understand better why some social networking services succeed while others don’t.

Social networks consist of people who are connected by a shared object. That’s why many sociologists, especially activity theorists, actor-network theorists and post-ANT people prefer to talk about ‘socio-material networks’, or just ‘activities’ or ‘practices’ (as I do) instead of social networks.

Approaching sociality as object-centered is to suggest that when it becomes easy to create digital instances of the object, the online services for networking on, through, and around that object will emerge too.

Practice Turn in Contemporary Theory,
by Theodore R. Schatzki (Editor), Karin Knorr Cetina (Editor), Eike von Savigny (Editor) “References to shared practices or to agreement in practice have long figured in the discourse of sociologists, but in recent years they have taken on…”
New York, University of Chicago Press, 2000.

I think, although the book introduction says that the semiotic views are not in accordance with practice theory, there must still be relationship of interpreting the object-centered networks with the cultural semiotic ideas.

The Practice Turn in Contemporary Theory is the first book to provide an exciting and diverse philosophical exploration of the role of practice and practices in human activity. It also shows how practice theory stands in opposition to numerous prevalent ways of thinking, such as structuralism, system theory, semiotics, and many strains of humanism.

As i could not acces the Cetina’s book, I looked for her other papers. The only one our libary has access is thisone. I find it meaningful, she builds her ideas around the notion of intersubjective objects.

Karin Knorr Cetina (2002) wrote in The Market as an Object of Attachment: Exploring Postsocial Relations in Financial Markets. By: Cetina, Karin Knorr; Bruegger, Urs. Canadian Journal of Sociology, Spring2000, Vol. 25 Issue 2, p141-168:

Two persons watching the same event are brought into a “state of intersubjectivity” by their experience evidently changing in similar ways, in response to what unfolds. The basis of this sort of we experience, for Schutz, was the temporal immediacy of events. Temporal immediacy allows one to recognize and follow another person’s experience of the third object as contemporaneous with one’s own experience.

Schutz, Alfred. 1964. Collected Papers II: Studies in Social Theory, edited and introduced lyy Arvid Broodersen. The Hague: Nijhoff.
Schutz, Alfred. 1967. The Phenomenology ofthe Social World. Evanstcm, HI.: Northwestern University Press.
Schutz, Alfred, and Thomas Luckmann. 1973. The Structures of the Life-World. Evanston, HI.: Northwestern University Press.

affordances evoked by social interaction

From AFFORDANCES FOR INTERACTION: THE SOCIAL IS MATERIAL FOR DESIGN
William W. Gaver

Gaver, W. W. (1996). Affordances for interaction: the social is material for design. Ecological Psychology, 8(2), 111–129.
http://www.cs.ubc.ca/labs/spin/publications/related/gaver96.pdf

Gaver describes affordances not as perception-based relative aspects of the environment that become noticed in activities (like Gibson’s affordances), but goes beyond it claiming that there are affordances, which are not perceptible per se, but which emerge due to interaction and actions in the environment.

There is a tendency to invoke sociological and anthropological constructs such as “communities of practice” or “social convention” rather than recognising the degree to which social activities are embedded in and shaped by the material environment.

Seemingly similar material conditions are incorporated into seemingly different social behaviours.

The concept of affordances, as introduced by Gibson (e.g., 1979), provides a way to describe the world that cuts across traditional subject-object dualities. Affordances go beyond value-free physical descriptions of the environment by expressing environmental attributes relative to humans.
At the same time, they go beyond subjective interpretations (e.g., associations, schemas, or social conventions) by describing meaning relative to an objective physical world.

Affordances are primarily facts about action and interaction, not perception. This contrasts with the common impression that affordances refer to—approximately—situations in which one can see what to do.

They allow meaning to be understood in terms of the relations of humans and their environment.
When affordances are perceived, a tight link between perception and action may ensue. But the concept is also useful in describing situations in which perceptual information is misleading about possibilities for action, or those in which affordances exist but information for them does not. In general, the perceptibility of an affordance should not be confused with the affordance itself.

Affordances exist not just for individual action, but for social interaction as well. Research on “social affordances” (e.g., Still & Good, 1991; Goldring, 1991) focuses on the possibilities for action that people offer one another and on the role of other people in pointing out new affordances (e.g., to babies). These are not social affordances, as defined above, but affordances for sociality.

Examples:

The interpretation given to unanswered communications varies depending on the medium. For instance, the delay between sending postal mail and deciding it has gone unanswered is much longer than that between dialling a telephone number and deciding it will not be picked up.

The properties of email also constrain the social interactions that it mediates. Because email is newer, less predictable, and more varied than other media, however, the behaviours that form are less stable and more open to examination. Subcultures have formed whose uses of email vary analogously to the differences between telephone and postal mail use. Some groups use email incessantly, monitoring it continuously and replying to messages almost immediately after they are received. Others use email only occasionally, reading new messages once a day or less, and replying to them only after some period of thought. And some regard email as a high-tech curiosity to which they would never entrust any important communication.

These communities do not reflect arbitrary differences in local culture, however, but the affordances of the email systems they use. If email is troublesome to access, slow, difficult to operate, prone to breakdown, and expensive, then intensive email cultures are unlikely to develop around it. If email systems are slow, they may be used analogously to postal mail – relatively formally and infrequently. If they are unreliable, then they cannot support formal communication well at all and will tend to be used as an unimportant novelty.

A range of social behaviours can thus form around the differing affordances of email, with the fact that it is viewed as a single medium confusing their coordination. Unanswered email will be interpreted differently by the two communities.
Moreover, the sender and recipient may have different interpretations of the same unanswered email, leading to new confusion and tensions.
The differences themselves are unavailable, or at least not obvious, to the sender and recipient.

Analysing the affordances offered by media spaces is useful in understanding their differences from the everyday medium, in part because it suggests design possibilities relatively directly (Gaver, 1991). Several limitations on the perceptual information media spaces convey become clear from such an analysis.

Perhaps the most important affordance of the everyday world lacking in media spaces is the ability to move. As Gibson (1979) emphasised, movement is fundamental for perception.
We move towards and away from things, look around them, and move them so we can inspect them closely. Movement might allow people to compensate for the discontinuities and anisotropies of current media spaces (Gaver, 1992; c.f. Heath & Luff, 1991). Social interactions in media space would be better supported if people could explore remote sites as easily as they can move around their own rooms.

The ecological approach is useful in the design process because it describes perception and interaction in terms of the properties of the environment, as well as those of people, and design is fundamentally about manipulating the environment for people.
Thus the ecological approach challenges researchers to avoid the temptation of using memory and inference in explanations of perception, and encourages them instead to discover the possibly high-level physical attributes that serve as information about the world.

From
Designing Electronic Collaborative Learning Environments
Paul Kirschner
Jan-Willem Strijbos
Karel Kreijns
Pieter Jelle Beers
Kirchner, P., Strijbos, J-W., Kreijns, K. & Beers, B. J. (2004). Designing electronic collaborative learning environments. ETR&D, 52(3), 47–66.
http://www.onderwijsstudies.leidenuniv.nl/content_docs/Strijbos/kirschner_et_al_2004__designing_electronic_collaborative_learning_environments_etrd_52_3_47-66.pdf

The authors distinguish between technological, educational and social affordances. It seems they rely mainly on the perceptable concept of affordances in case of technological and educational affordances and isocial affordances, the affordance concept of Gaver which suggests that interaction itself in the collaborative system, might determine some affordances differently is not emphasised much in case of social affordances.

The question is not what outcomes specific educational techniques and collaborative work forms cause, but rather what activities they actually afford, also often referred to as the affordances of a learning environment. Specific types of learning need to be afforded in different ways (i.e., different opportunities provided for learning) because the learners perceive and interact with each other and with the environment differently.

An affordance is, by definition, characterized by two relationships. First, there must be a reciprocal relationship between the organism and the environment.

The affordances must be perceivable and meaningful so that they can be used and must support or anticipate an action.

Second, there must be a perception-action coupling.

In Gibson’s (1977) view, natural selection has tuned a species’ effectivities to the affordances associated with its niche or occupation (Allen & Otto, 1996). In
Gibson’s terms, effectivities (i.e., one’s capabilities for action) allow humans to exploit their world just as effectivities such as wings allow birds to exploit the air for travel and the branches of trees for nesting.

Norman (1988) linked affordances to an object’s usability, and thus these affordances are designated technological or technology affordances (Gaver, 1991).

Kreijns, Kirschner, and Jochems (2002) defined social affordances—analogous to technological affordances—as the “properties of a CSCL environment that act as social-contextual facilitators relevant for the learner’s social interaction” (p. 13).

Kirschner (2002) defined educational affordances as those characteristics of an artifact that determine if and how a particular learning behavior could possibly be enacted within a given context.

The last interaction-design sequence suggests that the affordances are derived from learners’ behaviour, translated to the affordances by developers, tested in activity through learner’s perception and action and then evaluated on the basis of effectiveness on learning.

At iCamp Madrid meeting we discussed how should we define the necessary pedagogical (now i would rather use the concept educational due to different connotation of pedagogy term in german and british educational systems) affordances evoked by actions, which should meet the educational affordances of supposed tools; what would happen if we define these affordances teacher-centered way. The 6-stage interaction-design sequence suggest we should collect the web 2.0 learning activities first, and then derive the educational affordances from user’s behaviours in actions with tools.
The ideas of Gaver suggest that we will never be able of defining educational affordances in actions objective and definitive way, rather there exists the fuzzy set of affordances each user might act upon in interactive settings.
I like the idea that not all the educational affordances can be directly perceived by senses (eyes, ears), there are educational affordances of tools (e.g. support_community_sharedmeaning) which have intersubjective nature and which exist as the sum of shared perception plus the sythesis of what was perceived.