This master thesis presents an exploratory study on Interaction Design (IxD) for and with seniors. It includes two papers. The first paper is an exhaustive literature review, which investigates IxD research for the elderly at the CHI conference from 2000 to 2019. 90 related full papers and 125 extended abstracts have been identified for final analysis. During the literature review, the papers are classified into five research purposes, eight methods and eleven categories of topics. The results provide an overview of the current progress and trends in IxD research for older adults. The second paper is an empirical and exploratory study based on the findings of the first paper. It investigates how to conduct co-design remotely with and for older adults. The design practice includes surveys, a group design workshop and two rounds individual usability testing, which were all carried out online. The paper presents the challenges and opportunities of the conducted online design activities and concludes by providing suggestions for future co-design practices under similar circumstances.