中文摘要：

本研究以眼动仪为工具，采用移动窗口范式来考察小学五年级语文学优生和学困生的阅读知觉广度。实验结果发现，小学五年级语文学优生的阅读知觉广度范围为注视字左侧一个汉字到注视字右侧三个汉字，小学五年级语文学困生的阅读知觉，。度范围为注视字左侧一个汉字到注视字右侧两个汉字。小学五年级语文学优生的阅读知觉广度大于学困生。

英文摘要：

The perceptual span is the area of effective vision from which useful information can be obtained during a fixation in reading. Previous studies have showed that the perceptual span changed as a function of reading skill （Rayner, 1986）. Chinese is quite different from Western languages. The poor readers in Chinese have poor test scores. It has been predicted that the poor readers in Chinese have a smaller perceptual span. So the present study was conducted to explore if the reading skill level modulated the amount of information acquired during a fixation in Chinese reading. A total of 17 poor readers and 17 good readers in the fifth grade participated in the experiment. Their eye movements were recorded with a SR Research EyeLink 2000 eye tracker. Participants read 80 sentences with eight experimental conditions. The experiment design was 2 （skill level： good and poor reader in fifth grade） x 8（display conditions： no preview, R1, R2, R3, R4, L1R4, I2R4, and whole line condition） mixed design. The stimuli were presented in black on a white background. Participants were seated 90 cm from the monitor. The size of a character was 30 x 30 pixels, subtended 0.7~ of visual angle. Latin square design was adopted in the experiment. Various display conditions were blocked, and the order of conditions was counterbalanced across participants. The whole experiment lasted about 30 minutes. The results showed that the perceptual span of poor readers in the fifth grade was one character to the left of current fixation and two characters to its right. The results on mean fixation duration and reading speed eye movement measures supported one character space to the right of the fixated character, while forward saccade size measure supported two characters space to its right. The perceptual span of good readers in the fifth grade was one character to the left of current fixation and three characters to its right. The results on mean fixation duration and reading speed measures supported two characters space to th