Abstract Purpose: To develop a retinal degeneration model with selective photoreceptor loss and RPE sparing, to be used as recipient for evaluating retinal transplants. Methods: Albino rats were exposed to blue light, continuously, for 1–7 days (24–168 h) in a specially designed cage. Eyes were histologically analyzed at periods between 2 h and 8 months after the light exposure. Electroretinograms (ERGs) were recorded from some rats at 12–216 days after exposure. Using behavioral methods, visual thresholds of some rats were determined before exposure and re-measured between 18 and 52 days following exposure. Results: Apoptotic nuclei appeared exclusively in the photoreceptor layer after 1–5 days exposure to blue light. Light microscopy revealed that 2–4 days of light exposure reduced the outer nuclear layer (normally eight to ten rows) to 1 row of cells in the central retina and to two to three rows in the periphery, both in the superior and the inferior retina. Average ERG a- and b-wave amplitudes of light-damaged rats were both reduced by about 98%. Visual performance in the behavioral test was substantially impaired. Conclusions: Continuous exposure of albino rats to moderate blue light for 2–5 days selectively eliminates most of the photoreceptors while leaving the RPE initially intact.

Content-based automated scoring has been applied in a variety of science domains. However, many prior applications involved simplified scoring rubrics without considering rubrics representing multiple levels of understanding. This study tested a concept-based scoring tool for content-based scoring, c-rater™, for four science items with rubrics aiming to differentiate among multiple levels of understanding. The items showed moderate to good agreement with human scores. The findings suggest that automated scoring has the potential to score constructed-response items with complex scoring rubrics, but in its current design cannot replace human raters. This article discusses sources of disagreement and factors that could potentially improve the accuracy of concept-based automated scoring. © 2014 by the National Council on Measurement in Education.

© ISLS. Rapid advancements in computing have enabled automatic analyses of written texts created in educational settings. The purpose of this symposium is to survey several applications of computerized text analyses used in the research and development of productive learning environments. Four featured research projects have developed or been working on (1) equitable automated scoring models for scientific argumentation for English Language Learners, (2) a real-time, adjustable formative assessment system to promote student revision of uncertainty-infused scientific arguments, (3) a web-based annotation tool to support student revision of scientific essays, and (4) a new research methodology that analyzes teacher-produced text in online professional development courses. These projects will provide unique insights towards assessment and research opportunities associated with a variety of computerized text analysis approaches.