Text reading speed in a language with a shallow orthography benefits less from comprehension as reading ability matures

Background Reading can be assessed using different materials, including non-words and texts. Unlike reading words or non-words, reading a text may be supported by reading comprehension, and the extent of this support could change with the amount of schooling. Aim The present study aimed to examine how reading decoding in a shallow orthography like Italian changed with years of schooling, depending on the type of material and the contribution of non-word reading and reading comprehension to text reading speed. Methods Six hundred and forty two typically developing Italian students from 8 to 16 years old were involved. They were administered grade-appropriate tasks assessing text reading speed, non-word reading speed, and reading comprehension. Results The results showed that, although the two reading speed measures correlated closely, non-word reading speed improved only slightly with age, while the increase in text reading speed was steeper. Reading comprehension was a significant direct predictor of text reading speed after controlling for non-word reading speed. Importantly, however, while the difference in reading speed between non-words and text widened with schooling, the role of reading comprehension declined significantly, the Delta R-2 dropping from .10 in primary school to just .01 in high school. Conclusions These findings and their implications are discussed in the light of the relationship between reading comprehension and reading speed in a language with a shallow orthography across school grades.