Ability-Based Design offers a design approach to support practitioners in creating accessible and indivually optimized systems through a shift in focus on abilities instead of disabilities. As such, it could help to minimize moments of exclusion through technology and offer support for people, especially during times of crisis or social distancing as caused by the COVID-19 pandemic. However, in its current theoretically coined state, the approach includes no instruction on how to achieve this shift in mindset and how to apply a focus on abilities when designing systems. Within my thesis, I address this gap in research by analyzing ways for modeling users based on their abilities. For this, I propose ability models as user representation, identify the challenges as well as potentials of such ability models, and examine how this approach for the personalization of systems can help and support user populations. The overall aim and expected benefit of this research is to provide adequate techniques on how to include abilities into design considerations as well as an understanding of what accommodating for abilities might change, achieve or effect in terms of HCI research and design.