2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/15617We report in details the observations of structures in coupled map lattice during its chaotic evolution, both in one and two dimension, driven by identical noise on each site (by a structure we mean a group of neighboring lattice-sites for whom values of dynamical variable follow certain prespecified pattern). It is observed that the number of these structures decays with their size following a power-law, for a given noise-strength. The number of structures decays with their lifetime following a stretched exponential. We have seen an interesting phenomenon, which we call stochastic coherence, in which the average length as well as the average lifetime of these structures exhibit bell-shaped maxima for some intermediate range of noise-strength values. Similar features have also been observed for `spatio-temporal structures'.15 pages LaTeX file for text, 20 Postscript files for figures. Communicated to Physica DChaotic DynamicsAdaptation and Self-Organizing Systemstext