Whilst it is generally accepted as a positive criterion, affordance only gives the weakest of hints for interactive systems designers. This paper shows how useful it is to consider affordance as generated by a correspondence between program symmetries and user interface symmetries. Symmetries in state spaces (for instance, as might be visualised in statecharts) can be carried through to user in...

I briefly trace the topics presented in the 4 symposium papers in a cyclic order. Sheena Rogers’ (this issue) paper discussing an example of J. J. Gibson’s sense of ’information’ (the horizon ratio) and Eleanor J. Gibson’s (this issue) paper discussing affordance learning bring together the 2 core concepts of ecological psychology (information and affordance). Robert Lickliter (this issue) and ...

What should and should not be considered an affordance is still an open issue. At the 2002 North American meeting of the International Society for Ecological Psychology, a symposium was held concerning this topic. The articles in this special issue are expanded versions of the papers presented at that symposium. To set the stage for those discussions, this article presents an analysis of the ev...

Planning algorithms for non-deterministic domains are often intractable in large state spaces due to the well-known “curse of dimensionality.” Existing approaches to address this problem fail to prevent the planner from considering many actions which would be obviously irrelevant to a human solving the same problem. We formalize the notion of affordances [7] as knowledge added to an MDP that pr...

Ancient Eastern thought posited the ontological integration of the "mind-body world". The body-mind syncretism was a foundational precept in Eastern philosophy in which "Gih" ("Qi") was considered the basic entity of the universe and the human being. This study attempts to build a meta-theory and to demonstrate empirical designs for Gih, discussing the problems of the mind and body, or the subj...

We address the issue of learning and representing object grasp affordance models. We model grasp affordances with continuous probability density functions (grasp densities) which link object-relative grasp poses to their success probability. The underlying function representation is nonparametric and relies on kernel density estimation to provide a continuous model. Grasp densities are learned ...

Planning algorithms for non-deterministic domains are often intractable in large state spaces due to the well-known “curse of dimensionality.” Existing approaches to address this problem fail to prevent the planner from considering many actions which would be obviously irrelevant to a human solving the same problem. We formalize the notion of affordances [7] as knowledge added to an MDP that pr...

The actualization of affordances can often be accomplished in numerous, equifinal ways. For instance, an individual could discard an item in a rubbish bin by walking over and dropping it, or by throwing it from a distance. The aim of the current study was to investigate the behavioral dynamics associated with such metastability using a ball-to-bin transportation task. Using time-interval betwee...