create experiences for different device
types (that is, A or B). In MDXs, different devices are used simultaneously
for task completion (that is, A and B).
Digital assistants can capitalize on
the complementary input and output
capabilities of multiple devices for
new “better together” experiences.
Although the majority of sold smart
speakers lack screens, their capabili-
ties continue to expand, for example,
through the introduction of “smart
Multi-device experiences (MDXs) span-
ning multiple devices simultaneously
are viable for many individuals. Each
device has unique strengths in aspects
such as display, compute, portability,
sensing, communications, and input.
Despite the potential to utilize the port-
folio of devices at their disposal, people
typically use just one device per task;
meaning they may need to make com-
promises in the tasks they attempt or
may underperform at the task at hand.
It also means the support that digi-
tal assistants such as Amazon Alexa,
Google Assistant, or Microsoft Cortana
can offer is limited to what is possible
on the current device. The rise of cloud
services, coupled with increased owner-
ship of multiple devices, creates oppor-
tunities for digital assistants to provide
improved task completion guidance.
Case for Multi-Device
Arguments in favor of multi-device
support are not new. Cross-device ex-
periences (CDXs) and MDXs have been
discussed in the literature on interac-
tion design, human factors, and per-
vasive and ubiquitous computing. 2, 8
CDXs have focused on scenarios such
as commanding (remote control),
casting (displaying content from one
device on another device), and task
continuation (pausing and resuming
tasks over time). In CDXs, devices are
often used sequentially (that is, device
A then device B) and are chosen based
on their suitability and availability.
Tools such as the Alexa Presentation
Language (APL) enable developers to
Increased availability of cloud services and ownership of multiple
digital devices create unique opportunities for digital assistants
to provide guidance across a range of tasks and scenarios.