 The long-term goal is to help family caregivers of seriously ill patients be better prepared to serve as surrogate decision-makers when their loved ones can no longer make medical decisions for themselves. Research shows that family caregivers find surrogate decision-making highly stressful and emotionally burdensome, in part because they feel unprepared for surrogate decision-making. To date, no studies have determined which advance care planning ACP process best prepares caregivers for this role. The investigators prior work shows that a computer-based decision aid can help patients make more informed decisions and communicate their wishes more effectively. The investigators now propose to determine if family caregivers of patients with life-threatening illnesses are better prepared for surrogate decision-making: 1 when they engage in a structured ACP process together with patients; and 2 when they use this online decision aid for ACP. This will be accomplished via a randomized, controlled trial with a 2 x 2 factorial design comprising 4 groups: Standard ACPPatient Alone Group 1, Decision AidPatient Alone Group 2, Standard ACPPatients and Caregivers Together Group 3, and Decision AidPatients and Caregivers Together Group 4. 