This project is associated with the following paper: Wilson, A. C., & Bishop, D. V. M. (2020). Registered report: Investigating a preference for certainty in conversation among autistic adults compared to dyslexic adults and the general population. *PeerJ, 8*, e10398. https://doi.org/10.7717/peerj.10398 We are very happy to share materials for the assessments used in the study. However, we are conscious that making materials openly available may affect their validity for research and clinical uses if individuals have seen them in full prior to an assessment. Therefore, we have uploaded the full assessments as private components (entitled Implicature Comprehension Test and Grammaticality Decision Test) and we ask researchers wishing to use the materials to contact us for a link. Please see our ORCID accounts for contact details. https://orcid.org/0000-0001-7077-1618 https://orcid.org/0000-0002-2448-4033 In addition, a few example items are publicly available in the relevant components.