Search

We recently proposed the Creative Reasoning Test (CRT), a test for reasoning in ill-defined problem spaces. The test asks children who first performed the Standard Progressive Matrices test (SPM) to next generate an SPM-style test item themselves. The item is scored based on different aspects of its complexity. Here we introduce a method to provide separate sub scores for convergent and divergent production. A sample of 205 children from Grades 1 to 4 performed in both SPM and CRT, followed by a standard creativity test, the Test of Creative Thinking-Drawing Production (TCT-DP). We considered developmental aspects of the CRT scores as well as how they relate to classical reasoning and creativity test scores. Whereas the convergent production sub score of the CRT correlated with the SPM, the divergent production sub score correlated with the TCT-DP and no correlation was observed between both sub scores of the CRT. We concluded that convergent and divergent abilities in creative production can be assessed independently, within the same knowledge domain as classical problem solving. (Contains 7 tables and 2 figures.)

Novice designers produced a sequence of sketches while inventing a logo for a novel brand of soft drink. The sketches were scored for the presence of specific objects, their local features and global composition. Self-assessment scores for each sketch and art critics' scores for the end products were collected. It was investigated whether the design evolves in an essentially random fashion or according to an overall heuristic. The results indicated a macrostructure in the evolution of the design, characterized by two stages. For the majority of participants, the first stage is marked by the introduction and modification of novel objects and their local and global aspects; the second stage is characterized by changes in their global composition. The minority that showed the better designs has a different strategy, in which most global changes were made in the beginning. Although participants did not consciously apply these strategies, their self-assessment scores reflect the stages of the process.

In this paper, we propose a solution to the problem of adaptive control and parameter estimation in systems with unstable target dynamics. Models of uncertainties are allowed to be nonlinearly parameterized, and required to be smooth and monotonic functions of linear functionals of the parameters. The mere assumption of existence of nonlinear operator gains for the target dynamics is sufficient to guarantee that system solutions are bounded, reach a neighborhood of the target set, and the mismatches between the modeled uncertainties and their compensator converge to zero. With respect to parameter convergence, a standard persistent excitation condition suffices to ensure that it is exponential. When a weaker, nonlinear version of persistent excitation is satisfied, asymptotic convergence is guaranteed. The spectrum of possible applications ranges from tyre-road slip control to asynchronous message transmission in spiking neural oscillators. Index Terms--Adaptive control, exponential convergence, monotone functions, nonequilibrium dynamics, nonlinear parametrization, (nonlinear) persistent excitation, parameter estimation, unstable.