A new dynamic tactile display for reconfigurable braille: implementation and tests

Different tactile interfaces have been proposed to represent either text (braille) or, in a few cases, tactile large-area screens as replacements for visual displays. None of the implementations so far can be customized to match users' preferences, perceptual differences and skills. Optimal choices in these respects are still debated; we approach a solution by designing a flexible device allowing the user to choose key parameters of tactile transduction. We present here a new dynamic tactile display, a 8 × 8 matrix of plastic pins based on well-established and reliable piezoelectric technology to offer high resolution (pin gap 0.7mm) as well as tunable strength of the pins displacement, and refresh rate up to 50s(−1). It can reproduce arbitrary patterns, allowing it to serve the dual purpose of providing, depending on contingent user needs, tactile rendering of non-character information, and reconfigurable braille rendering. Given the relevance of the latter functionality for the expected average user, we considered testing braille encoding by volunteers a benchmark of primary importance. Tests were performed to assess the acceptance and usability with minimal training, and to check whether the offered flexibility was indeed perceived by the subject as an added value compared to conventional braille devices. Different mappings between braille dots and actual tactile pins were implemented to match user needs. Performances of eight experienced braille readers were defined as the fraction of correct identifications of rendered content. Different information contents were tested (median performance on random strings, words, sentences identification was about 75%, 85%, 98%, respectively, with a significant increase, p < 0.01), obtaining statistically significant improvements in performance during the tests (p < 0.05). Experimental results, together with qualitative ratings provided by the subjects, show a good acceptance and the effectiveness of the proposed solution

Acomodaciones computarizadas para la evaluación de comprensión lectora en estudiantes con limitación visual

A nivel mundial se ha estimado que 285 millones de personas tienen discapacidad visual. La inclusión educativa de personas con limitación visual (LV) resulta compleja ya que el acceso a gran parte de los recursos educativos se obtiene a través del canal visual. Así, es necesaria la implementación de modificaciones en los formatos de presentación de dichos recursos para que resulten accesibles a esta población por medio de canales sensoriales alternativos al convencional. El objetivo general del presente estudio fue comparar el desempeño en comprensión lectora según la acomodación utilizada en estudiantes con y sin limitación visual de la ciudad de Bogotá. Para esto, se implementó un Test Adaptativo Informatizado (TAI) y se emplearon tres tipos de acomodaciones: TAI auditivo, TAI visual y lector humano. No se encontraron diferencias significativas en el desempeño de los evaluados con LV en las modalidades de acomodación auditiva del TAI y la acomodación con lector (p.05). Sin embargo, sí se encontraron diferencias significativas (p.05) en el desempeño en comprensión lectora entre estudiantes con LV que tomaron la acomodación auditiva del TAI y los estudiantes sin LV que tomaron la acomodación visual del TAI, siendo los estudiantes sin LV quienes obtuvieron mayor desempeño. A pesar de que no se comprobaron las hipótesis planteadas, el presente estudio ofrece una primera propuesta metodológica sustentada en evidencia empírica para la implementación de sistemas de evaluación alternativos basados en tecnologías informatizadas que resulten coherentes con las políticas de inclusión educativa y por ende, promuevan la justicia en los procesos de evaluación. Se sugiere para futuros estudios, evaluar la conceptualización del constructo comprensión lectora y recopilar evidencias de validez de las acomodaciones de prueba.Abstract. It has been reported that around 285 million people worldwide have visual impairment. Since access to most educational resources requires vision, educational inclusion of people with visual impairment (VI) is a complex task. Thus, changes in the format of educational resources are needed so that students with VI can access them through alternate senses like hearing. The purpose of this study was to compare reading comprehension performance according to the accommodation in Colombian students with and without visual impairment. A Computerized Adaptive Test (CAT) was used along with three accommodations: audio CAT, visual CAT and human reader. No significant differences (p.05) were found in reading comprehension performance of student with VI between audio CAT and human reader accommodations. However, significant differences were found (p .05) in reading comprehension performance between student with VI who took the audio CAT and students without VI who took the visual CAT. Students without VI had higher performance. Even though research hypothesis were not confirmed, this study offers an alternate methodological approach based on empirical evidence to introduce alternative computer-based assessment systems that are consistent with educational inclusive policies and therefore, promote justice in assessment. It is suggested that future studies assess the theoretical framework of reading comprehension and gather validity evidence of test accommodations.Maestrí