299,257 research outputs found
POWERPLAY: Training an Increasingly General Problem Solver by Continually Searching for the Simplest Still Unsolvable Problem
Most of computer science focuses on automatically solving given computational
problems. I focus on automatically inventing or discovering problems in a way
inspired by the playful behavior of animals and humans, to train a more and
more general problem solver from scratch in an unsupervised fashion. Consider
the infinite set of all computable descriptions of tasks with possibly
computable solutions. The novel algorithmic framework POWERPLAY (2011)
continually searches the space of possible pairs of new tasks and modifications
of the current problem solver, until it finds a more powerful problem solver
that provably solves all previously learned tasks plus the new one, while the
unmodified predecessor does not. Wow-effects are achieved by continually making
previously learned skills more efficient such that they require less time and
space. New skills may (partially) re-use previously learned skills. POWERPLAY's
search orders candidate pairs of tasks and solver modifications by their
conditional computational (time & space) complexity, given the stored
experience so far. The new task and its corresponding task-solving skill are
those first found and validated. The computational costs of validating new
tasks need not grow with task repertoire size. POWERPLAY's ongoing search for
novelty keeps breaking the generalization abilities of its present solver. This
is related to Goedel's sequence of increasingly powerful formal theories based
on adding formerly unprovable statements to the axioms without affecting
previously provable theorems. The continually increasing repertoire of problem
solving procedures can be exploited by a parallel search for solutions to
additional externally posed tasks. POWERPLAY may be viewed as a greedy but
practical implementation of basic principles of creativity. A first
experimental analysis can be found in separate papers [53,54].Comment: 21 pages, additional connections to previous work, references to
first experiments with POWERPLA
Moral Particularism and the Role of Imaginary Cases: A Pragmatist Approach
I argue that John Dewey’s analysis of imagination enables an account
of learning from imaginary cases consistent with Jonathan Dancy’s moral
particularism. Moreover, this account provides a more robust account of learning
from cases than Dancy’s own. Particularism is the position that there are no, or at
most few, true moral principles, and that competent reasoning and judgment do not
require them. On a particularist framework, one cannot infer from an imaginary
case that because a feature has a particular moral importance there, that it must
have that import in an actual case. Instead, for Dancy, cases can yield “reminders,”
and a person with a lot of experience (real or imagined) brings a “checklist” of
features that can matter to a situation. Using the Nathan-David exchange from
2 Samuel and Martha Nussbaum’s “Steerforth’s Arm” from Love’s Knowledge,
I show that this account does not explain all instances of learning from cases.
Drawing on recent work on cases, I argue that cases can be educative by serving an
exploratory function, probing what one takes to be known and provoking change
in the background one uses in evaluating a situation. I then argue that Dewey’s
work on imagination in his comments on sympathy and in A Common Faith and
Art as Experience enables such a role for cases on a particularist framework. Mark
Johnson’s recent work on metaphor further illuminates how Dewey’s account of art
can be exploratory. I contend that this account affords an exploratory role for cases
consistent with Dancy’s particularism
Automation and schema acquisition in learning elementary computer programming: Implications for the design of practice
Two complementary processes may be distinguished in learning a complex cognitive skill such as computer programming. First, automation offers task-specific procedures that may directly control programming behavior, second, schema acquisition offers cognitive structures that provide analogies in new problem situations. The goal of this paper is to explore what the nature of these processes can teach us for a more effective design of practice. The authors argue that conventional training strategies in elementary programming provide little guidance to the learner and offer little opportunities for mindful abstraction, which results in suboptimal automation and schema acquisition. Practice is considered to be most beneficial to learning outcomes and transfer under strict conditions, in particular, a heavy emphasis on the use of worked examples during practice and the assignment of programming tasks that demand mindful abstraction from these examples
Neuron as a reward-modulated combinatorial switch and a model of learning behavior
This paper proposes a neuronal circuitry layout and synaptic plasticity
principles that allow the (pyramidal) neuron to act as a "combinatorial
switch". Namely, the neuron learns to be more prone to generate spikes given
those combinations of firing input neurons for which a previous spiking of the
neuron had been followed by a positive global reward signal. The reward signal
may be mediated by certain modulatory hormones or neurotransmitters, e.g., the
dopamine. More generally, a trial-and-error learning paradigm is suggested in
which a global reward signal triggers long-term enhancement or weakening of a
neuron's spiking response to the preceding neuronal input firing pattern. Thus,
rewards provide a feedback pathway that informs neurons whether their spiking
was beneficial or detrimental for a particular input combination. The neuron's
ability to discern specific combinations of firing input neurons is achieved
through a random or predetermined spatial distribution of input synapses on
dendrites that creates synaptic clusters that represent various permutations of
input neurons. The corresponding dendritic segments, or the enclosed individual
spines, are capable of being particularly excited, due to local sigmoidal
thresholding involving voltage-gated channel conductances, if the segment's
excitatory and absence of inhibitory inputs are temporally coincident. Such
nonlinear excitation corresponds to a particular firing combination of input
neurons, and it is posited that the excitation strength encodes the
combinatorial memory and is regulated by long-term plasticity mechanisms. It is
also suggested that the spine calcium influx that may result from the
spatiotemporal synaptic input coincidence may cause the spine head actin
filaments to undergo mechanical (muscle-like) contraction, with the ensuing
cytoskeletal deformation transmitted to the axon initial segment where it
may...Comment: Version 5: added computer code in the ancillary files sectio
The sociological imagination and its promise fifty years later: Is there a future for the social sciences as a free form of enquiry?
This paper offers a restatement of Wright Mills’ The Sociological Imagination and tries to judge whether its promise can be credibly renewed today by addressing the question about the present and future possibilities of the social sciences as free forms of enquiry. Relying on Weber, Mills and other thinkers, the paper sustains that the possibilities for a truly free social science essentially depend on three major ‘conditions’: the subjective stance or vocation, the sociological imagination proper, and an independent social science politics, conditions whose apt names can also be ‘love’, ‘insight’ and ‘courage’. An analysis of the presence and strength of each of these conditions in contemporary social science and in academia shows the magnitude of the task faced for the existence of a free social science
A community approach to road safety education using practical training methods : the Drumchapel project
Research shows that practical training methods, in which children receive guided experience of solving traffic problems in realistic traffic situations, are amongst the most effective in improving children's pedestrian competence. However, practical training is both time consuming and labour intensive, making it difficult to capitalise on the strengths of the method. The report describes a solution to this problem by adopting a community participation approach in which local volunteers carried out all roadside training, working in co-operation with schools and project staff. The project took place in an area of Glasgow known for its exceptionally high child pedestrian accident rate
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