Evidence of comparability is generally needed whenever there are variations in the conditions of an assessment administration, including variations introduced by the administration of an assessment on multiple digital devices (e.g., tablet, laptop, desktop). This article is meant to provide a comprehensive examination of issues relevant to the comparability of scores across devices, and as such provide a starting point in designing and implementing a research agenda to support the comparability of any assessment program. This work starts with a conceptual framework rooted in the idea of a comparability claim--a conceptual statement about how each student is expected to perform on each of the devices in question. Then a review of the available literature is provided, focusing on how aspects of the devices (touch screens, keyboards, screen size, and displayed content) and aspects of the assessments (content area and item type) relate to student performance and preference. Building on this literature, recommendations to minimize threats to comparability are then provided. The article concludes with ways to gather evidence to support claims of comparability.