Peculiaridades de la lectura táctil del braille. Un estudio empírico

Resumen

Este artículo ofrece una discusión sobre las posibles causas que pueden explicar por qué el desarrollo cognitivo de los ciegos presenta retrasos importantes en el período de las operaciones concretas, mientras que no presenta diferencias respecto a los videntes en tareas de tipo proposicional. Para ello se examinan tres posibles explicaciones: la influencia del modo de escolarización, las características del tacto y la remediación verbal. Se acaba concluyendo que estas dos últimas hipótesis son las que ofrecen una explicación más convincente. Los datos que aquí se aportan pare?en sostener la hipótesis dual sobre la representación de la información en la memoria.     

La segmentación de textos. El comportamiento evolutivo entre cinco y once años

Resumen

Mediante tareas de segmentación de textos, se investiga la evolución infantil en el conocimiento de las unidades gramaticales del castellano. Los datos demuestran dos niveles: I. Segmentación por las unidades ortográficamente correctas (espacios), y II. Segmentación por unidades superiores teniendo en cuenta las relaciones sintácticas. Se argumenta sobre la influencia escolar en la solución de estas tareas.     

Actividad conjunta y habla: una aproximación al estudio de los mecanismos de influencia educativa

Resumen

El artículo presenta las principales opciones teóricas y metodológicas de un proyecto de investigación cuyo objetivo principal es el estudio de algunos mecanismos de influencia educativa que se manifiestan en, o actúan a través de, la interacción profesor/grupo de alumnos y adulterino. Utilizando como punto de partida el concepto de interactividad, término acuñado para designar las formas de organización de la actividad conjunta en torno al contenido o tarea que están llevando a cabo los participantes, se analizan dos mecanismos de influencia educativa: la cesión y el traspaso progresivos del control y la responsabilidad y la construcción progresiva de sistemas de significados compartidos.     

California's emergency credential teachers: examining program conditions for sustainability and effectiveness

The Summer Institute for Teacher Education (SITE), a one-year program, emerged in response to a California State University directive to increase the number of credentialed teachers. This article explains the rationale and program approach, describes the participants of the first two cohorts—SITE 1999 and SITE 2000, and uses yearly program evaluations to discuss the program goals and outcomes. It concludes with implications for the preparation of teachers of color and the institutional conditions needed to promote sustainability and teacher effectiveness. Three goals differentiated SITE from the regular program: (1) to create a one-year credential program to increase the yearly number of credentialed elementary teachers, (2) to offer a program for training the growing number of California's emergency credentialed teachers, and (3) to provide the contextual conditions and?culturally responsive curricular content needed for successful sustained service to children, especially those attending high-poverty, low performing urban schools.     

Widely linear estimation for multisensor quaternion systems with mixed uncertainties in the observations

The optimal widely linear state estimation problem for quaternion systems with multiple sensors and mixed uncertainties in the observations is solved in a unified framework. For that, we devise a unified model to describe the mixed uncertainties of sensor delays, packet dropouts and uncertain observations by using three Bernoulli distributed quaternion random processes. The proposed model is valid for linear discrete-time quaternion stochastic systems measured by multiple sensors and it allows us to provide filtering, prediction and smoothing algorithms for estimating the quaternion state through a widely linear processing. Simulation results are employed to show the superior performance of such algorithms in comparison to standard widely linear methods when mixed uncertainties are present in the observations.     

A new tool to classifying new technology-based firm prospects and expectations

This is an exploratory insight into the profile and prospects of growth and success attached to one category of firms, the so-called New Technology-Based Firms (NTBFs). Analysis of our empirically based data from 30 NTBFs leads us to the Market-Technology-Entrepreneurial (M-T-E) Matrix, whose eight three-dimensional quadrants serve to classify high-tech new ventures by performance. A factorial analysis coupled with a discriminate analysis are the statistical tools employed in obtaining the M-T-E Matrix and ascribing predictive capacity to it.     

Psychometric properties of child- and teacher-reported curl-up scores in children ages 10-12 years

The purpose of this study was to examine the psychometric properties of child- and teacher-reported curl-up (CU) scores in children ages 10-12 years in both a norm-referenced (NR) and criterion-referenced (CR) framework. Eighty-four children, 36 boys and 48 girls, performed the FITNESSGRAM (Cooper Institute for Aerobics Research, 1992) CU test on 2 days separated by 48-72 hr. Two video cameras were used to record students' CU performances. Two students performed the CU at the same time, with each child's performance recorded by one camera. The test was terminated when the child stopped due to fatigue or after two form errors occurred. Teacher-reported scores were the average of two independent ratings of each video performance, while child-reported scores came from data collected and recorded by the children. Single trial norm-referenced reliability was R = .75 for girls and R = .80 for boys for teacher-reported CU and R = .69 and R = .70 for child-reported CU for girls and boys, respectively. CR reliability was examined using P, proportion of students who consistently passed or failed the test across 2 days, and km, defined as reliability with chance removed. For teacher-reported scores, P = .89 and km = .78 for boys and P = .81 and km = .62 for girls. For child-reported scores, P = .86 and km = .72 for boys, while P = .79 and km = .58 for girls. For teacher-reported data, 39% of boys passed and 50% failed the test on both days, while for girls the percentages were 27% pass and 54% fail. For child-reported data, 64% of boys passed and 22% failed on both days, while 54% of girls passed and 25% failed. NR validity was examined by correlating teacher and child-reported scores. The resultant coefficient was r = .42 (95% CI = .11-.66) for boys and r = .67 (95% CI = .58-.74) for girls. Additionally, child-reported scores were significantly higher than teacher-reported scores. CR validity was examined with a contingency coefficient, and results indicated C = .55 with 44% false master errors for boys and C = .65 with 29% false master errors for girls. The findings of this study suggest that while NR reliability estimates were moderate for teacher-reported scores, single trial estimates suggest that child-reported CU should be viewed with caution. In regard to CR reliability, both teacher-reported and child-reported reliability were moderate. However, there were marked differences between teacher- and child-reported scores, with children reporting higher percentages of students passing and lower percentage of student failing the test when compared with scores reported by teachers. Validity was rather moderate when viewed in either a NR and CR framework. It is suggested that problems with child-reported scores may be due to the need for additional practice or simplification of the testing protocol.     

Specific reading disability: Follow-up studies

Twenty-four children with specific reading disability, originally studied and treated at the Bellevue Hospital Mental Hygiene Clinic between 1949 and 1951, were reexamined as young adults between 1961 and 1962 with the battery of tests given to them ten to 12 years before. Their specific perceptual problems and evidence of lack of clear- out cerebral dominance persists, although in less severe form. Those patients who as children had neurological signs in addition to the specific reading disability showed less improvement than those who had none.