<p dir="ltr">These are datasets for 2 experiments that used a speeded grammaticality task to assess effects of providing explicit word boundary cues on the effects of the relative length of two adjacent transposed-words on the transposed-word effect in reading. These experiments were conducted in Chinese. Experiment 1 used interword spaces to provide explicit word boundary cues, comparing effects for naturally unspaced Chinese text and identical text that included interwork spaces. Experiment 2 used alternating green and red text to mark word boundaries. The summarised data sets provide accuracy scores and response times (in milliseconds) for correct responses. </p>