Numerical and Real-World Estimation Abilities of Deaf and Hearing College Students.

Various studies have examined possible loci of deaf learners' documented challenges with regard to reading, usually focusing on language-related factors. Deaf students also frequently struggle in mathematics and science, but fewer studies have examined possible reasons for those difficulties. The present study examined numerical and non-numerical (real-world) estimation skills among deaf and hearing college students, together with several cognitive abilities likely to underlie mathematics performance. Drawing on claims in the literature and some limited evidence from research involving deaf children, the study also considered the possibility that the use of sign language and/or the use of cochlear implants and spoken language might facilitate deaf college students' estimation skills and mathematics achievement more broadly. Results indicated relatively little impact of cochlear implant use or language modality on either estimation skills or overall mathematics ability. Predictors of those abilities differed for deaf and hearing learners. Results suggest the need to guard against overgeneralisations either within the diverse population of deaf learners or between deaf and hearing learners. They further emphasise the need for evidence-based practice in mathematics instruction appropriate for older deaf learners, rather than making assumptions from studies involving younger or narrowly-selected samples.