The overall system architecture of the envisioned adaptive accessibility component of the SlideWiki system is thus composed of an ontology (which we call the AccessibleOCW ontology), learner proﬁles, representations of the OCW components, and a personalization module.
1. AccessibleOCW ontology: our proposed ontology that contains the relevant accessibility knowledge required in OCW contexts (e.g., disability types, assistive technologies, accessibility guidelines, e-learning standards, etc.)
2. Learner proﬁle: are presentation of learners, including information about their disabilities. The disabilities can be either automatically detected or manually entered by the learners (or their caregivers) using a form. Other needs and preferences of the learners can then be inferred from their disabilities using the ontology.
3. OCW components: these are the website, educational resources, assessments, and collaboration tools. The OCW components are adapted according to the learner proﬁles.
4. Personalization module: processes the proﬁle and ontology as an input to retrieve the preferences, assistive technology requirements, accessibility guidelines and standards related to the learners. Based on this information, it adapts the OCW content to the individual needs and preferences of the learners, and suggests the most appropriate educational resources to them.