Significance: The International Reading Speed Texts (IReST) is a valid measure of reading speed in a Canadian sample. However, if clinicians desire to assess reading comprehension using the IReST, this will significantly reduce reading speeds of individuals with normal vision or reduced visual acuity and therefore should use the values presented here.
Purpose: The purposes of this study are (1) to validate the IReST in an English-speaking Canadian sample and (2) to examine how reading comprehension questions and reduced visual acuity affect reading speed on the IReST.
Methods: For study 1, Canadian English speakers (n = 25) read all 10 IReST following the procedures used in the original IReST validation. For study 2, Canadian English speakers (n = 50) read all 10 IReST, half with normal/corrected-to-normal vision and half with reduced visual acuity, and were asked reading comprehension questions.
Results: No significant differences were found between Canadian sample and the published IReST values (in all cases, P > .05; mean difference [Mdiff] = -5.30 to +11.43; Cohen d = -0.15 to +0.27; Bayes factors = 0.41, 0.09). Assessing reading comprehension with multiple-choice questions on the IReST significantly reduced reading speeds in the normal vision condition (Mdiff = 25.3; 95% confidence interval, -16.7 to -34.1) and in the simulated impairment condition (Mdiff = 59.3; 95% confidence interval, -47.7 to -71).
Conclusions: The IReST is a valid measure that can be used to assess reading speed in a Canadian English-speaking sample. If researchers/clinicians wish to assess both reading speed and comprehension, using multiple-choice reading comprehension questions, then the values provided by the IReST will likely underestimate an individual's true reading speed in individuals with normal/corrected-to-normal vision or reduced visual acuity.