Design and Validation of a Logarithmic Chinese Reading Acuity Chart

摘要

?Purpose?The design principles of MNREAD acuity chart have been successfully used in developing reading assessment instruments in several languages. Written Chinese are horizontally more compact than Latin. Each square character carries the meaning of several letters. Chinese characters have a wide range of spatial complexities. 1 to 20 or more strokes are packed in the same square area, resulting in a 0.2-0.3 log unit difference in acuity size. We applied some of the MNREAD principles to design a set of logarithmic reading charts for Simplified Chinese readers. ?Methods?The charts are made of 12-character simple declarative sentences selected from 1st to 3rd grade textbooks for elementary schools in China. The sentences are printed in single lines, because 12 characters can be easily fitted in a regular printing paper. 67 sentences were selected from a pool of 105, after eliminating those with too many or too few total number of strokes. Reading speed, word error and subjective rating on contents and fluency were tested in 20 Chinese college students to select the 48 sentences for 3 charts. Finer adjustments were made to replace less frequently used characters and to equalize the number of very simple characters (1 to 3 strokes). The 16 sentences in each logarithmic chart covered 20/10 to 20/320 acuity for a 40-cm reading distance. The charts were printed with ElectroInk. The physical character sizes were validated using a 15X measuring loupe. The mean numbers of strokes per sentence of the 3 charts were 87.2±3.5, 87.4±3.3 and 87.3±3.4. To validate the charts, 30 normal Chinese college students were tested with 2 randomly selected charts, scored using the MNREAD protocol. They also read two 150-character middle-school level continuous texts at a 0.7 logMAR print size. ?Results?The mean reading acuity (RAC), critical print size (CPS) and maximal reading speed (MRS) were 0.20 logMAR, 0.4 logMAR and 281 char/min. There were no significant differences in the parameters among the 3 charts (p=0.13, 0.84 & 0.59 for RAC, CPS and MRS). The test/retest reliabilities were 0.55, 0.35 and 0.91 for RAC, CPS and MRS. The maximal reading speed was correlated to that of continuous texts(r =0.87, p0.001). ?Conclusions?The new logarithmic Chinese reading acuity charts have demonstrated the accuracy and reliability required by a clinical instrument. They faithfully reflected the subject’s real-world reading performance. ?View OriginalDownload Slide?Chinese Reading Acuity Chart?Chinese Reading Acuity ChartView OriginalDownload Slide? Keywords: 672 reading ? 465 clinical (human) or epidemiologic studies: systems/equipment/techniques ?.