Design and Assessment of User Interface Optimized for Elderly People. A Case Study of Actgo-Gate Platform Topics: Autonomy and Active Ageing; Case Studies for AAL ; Flexible Occupation and Volunteering; Personalized Interfaces; Self-fulfillment and Social Participation; Systems Usability; Web and Mobile Interaction; Web Content Accessibility In Proceedings of the 3rd International Conference on Information and Communication Technologies for Ageing Well and e-Health ICT4AWE - Volume 1, 157-163, 2017 , Porto, Portugal