Designing Android Marshmallow volume controls: a user experience case study

When a user presses physical hardware volume keys on a smartphone, volume controls appears on the screen. Traditionally, these volume controls are represented by a single slider. Android's Lollipop release introduced new functionality into the volume controls: a way to temporarily silence interruptions from notifications and phone calls. After the launch of Android Lollipop, we discovered some usability issues with the more robust volume controls interface. We decided to address these issues in Android's next release, Marshmallow. In this case study, we describe the trade-offs we faced in designing Android Marshmallow volume controls and how our interdisciplinary user experience team designed a longitudinal study that helped us evaluate two designs we were considering. We also describe the impact of our research approach and how we arrived at a final design.